1 15 16 31 47 78 125 ? a) 172 b) 203 c) 139 d) 167 e) None of these

1 15 16 31 47 78 125 ?
a) 172
b) 203
c) 139
d) 167
e) None of these
by

1 Answer

Answer :

15 + 1 = 16
15 + 16 = 31
16 + 31 = 47
31 + 47 = 78
47 + 78 = 125
78 + 125 = 203
Answer: b)
by

Related questions

The average domestic investment in the year 2011 is what percent of the average investment in Transport during the given four years? a) 201% b) 65.34% c) 125.45% d) 147.97% e) 167.23%

Description : The average domestic investment in the year 2011 is what percent of the average investment in Transport during the given four years? a) 201% b) 65.34% c) 125.45% d) 147.97% e) 167.23%

Last Answer : b) 65.34%

55 60 67 78 91 108 ? a) 125 b) 121 c) 127 d) 89 e) None of these

Description : 55 60 67 78 91 108 ? a) 125 b) 121 c) 127 d) 89 e) None of these

Last Answer : 55 + 5 = 60 60 + 7 = 67 67 + 11 = 78 78 + 13 = 91 91 + 17 = 108+108 + 19 = 127 Answer: c)

3 7.5 15 37.5 75 167.5 375 a) 167.5 b) 75 c) 37.5 d) 15 e) 7.5

Description : 3 7.5 15 37.5 75 167.5 375 a) 167.5 b) 75 c) 37.5 d) 15 e) 7.5

Last Answer : The series is ×2.5, ×2 alternately Answer: a)

501/58 * 291/101 ÷ 31/155 = ? a) 140 b) 125 c) 95 d) 85 e) 110

Description : 501/58 * 291/101 ÷ 31/155 = ? a) 140 b) 125 c) 95 d) 85 e) 110

Last Answer : Answer: b)

When the integers from 1 to 999 are written on a paper, the number of zeros used in writing it is: a) 192 b) 189 c) 200 d) 203 e) 216

Description : When the integers from 1 to 999 are written on a paper, the number of zeros used in writing it is: a) 192 b) 189 c) 200 d) 203 e) 216

Last Answer : From 1 to 10 : 1 zero From 11-100 : 10 zeros (100 has 2 zeros) From 101 – 900 : 8×20 = 160 zeros From 901-999 : we have 18 zeros Total = 1+10+160+18 = 189 zeros Answer: b)

97,122,?,307,503,792 a) 171 b) 158 c) 186 d) 203 e) 178

Description : 97,122,?,307,503,792 a) 171 b) 158 c) 186 d) 203 e) 178

Last Answer : Answer: c)

What is the median of 120 132 142 119 112 130 149 111 167 139 141.?

Description : What is the median of 120 132 142 119 112 130 149 111 167 139 141.?

Last Answer : 112, 135, 124, 115, 119, 90, 112, 134, 113, 114, 115.

. The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C and the heat transfer co-efficient between the outer surface of wall and air is 20 W.m-2 .°C-1 . The rate of heat loss from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175

Description : . The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C ... from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175

Last Answer : (A) 165.4

4×(√3 + √4)2 + 6(√5 +√6)2 -3(√2 + √3)2 =? a) 167 b) 123 c) 157 d) 153 e) 149

Description : 4×(√3 + √4)2 + 6(√5 +√6)2 -3(√2 + √3)2 =? a) 167 b) 123 c) 157 d) 153 e) 149

Last Answer : ? =4(3+4+2√12) + 6(5+6+2√30)-3(2+3+2√6) =4(7+2√12)+6(11+2√30)-3(5+2√6) =28 + 8√12 + 66 + 12√30 – 15 - 6√6 =(28+66-15) + (8√12+12√30-6√6) =79 + (8√4 × 3 + 12√30 - 6√6) =79+16√3 + 12√30 - 6√6 =79 + 16 ×1.7 + 12 × 5.4 – 6 ×2.4 =79+27.2 + 64.8-14.4 = 156.6 = 157 Answer: c)

210, 154, 182, 168, 175,171.5, ? a) 172.75 b) 173.25 c) 172.25 d) 173.75 e) 174.75

Description : 210, 154, 182, 168, 175,171.5, ? a) 172.75 b) 173.25 c) 172.25 d) 173.75 e) 174.75

Last Answer : Starting from the third term, every term is the average of the previous two terms. Hence the next term is (175 + 171.5)/ 2 = 173.25 Answer: b)

1:1, 8:4, 9:27, 64:16, 25:125, ?:?, 49:343, a) 36:316 b) 216:36 c) 316:16 d) 32:316 e) None of these

Description : 1:1, 8:4, 9:27, 64:16, 25:125, ?:?, 49:343, a) 36:316 b) 216:36 c) 316:16 d) 32:316 e) None of these

Last Answer : Its alternatively ratio of n2 and n3 Now, after 25:125, it would be 63 : 62  216:36 Answer: b)

In a class there are 15 boys and 10 girls. Three students are selected at random. The difference between the probability that 2 boys and 1 girl are selected compared to 1 boy and 2 girls are selected is: a) 23/78 b) 19/88 c) 15/92 d) 4/23 e) 7/46

Description : In a class there are 15 boys and 10 girls. Three students are selected at random. The difference between the probability that 2 boys and 1 girl are selected compared to 1 boy and 2 girls are selected is: a) 23/78 b) 19/88 c) 15/92 d) 4/23 e) 7/46

Last Answer : 2 boys, 1 gi(Prl = (15c2×10c1) / 25c3 = 1050/2300 1 boy, 2 girls = (15c1×10c2) / 25c3 = 675/2300 Difference = (1050 - 675)/2300 = 375/2300 = 15/92 Answer: c)

15 17 21 29 45 77 ? a) 109 b) 125 c) 141 d) 173 e) None of these

Description : 15 17 21 29 45 77 ? a) 109 b) 125 c) 141 d) 173 e) None of these

Last Answer : 15 + 2 = 17 17 + 4 = 21 21 + 8 = 29 29 + 16 = 45 45 + 32 = 77 77 + 64 = 141 Answer: c)

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Description : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Last Answer : 22

15, 18, 21.6, 25.92, ? a) 31.104 b) 31.014 c) 31.114 d) 30.114 e) 30.004

Description : 15, 18, 21.6, 25.92, ? a) 31.104 b) 31.014 c) 31.114 d) 30.114 e) 30.004

Last Answer : The series is a geometric progression with a common ratio 1.2. Hence the next term is 25.92 × 1.2 = 31.104 Answer: a)

The ages of Gaurav and Goutham will be in the ratio 5 : 7 after ten years from now and will be in the ratio 13 : 18 after twelve years from now. Find the ratio of the sum of their ages 10 years hence to the sum of their ages 12 years hence. 1 : 25 : 27 2 : 13 : 15 3 : 14 : 17 4 : 18 : 23 5 : 30 : 31

Description : The ages of Gaurav and Goutham will be in the ratio 5 : 7 after ten years from now and will be in the ratio 13 : 18 after twelve years from now. Find the ratio of the sum of their ages 10 years hence to the sum of their ages 12 ... hence. 1 : 25 : 27 2 : 13 : 15 3 : 14 : 17 4 : 18 : 23 5 : 30 : 31

Last Answer : 5 : 30 : 31

53 × 47 + 64 × 56 -72 × 68 = ? a) 1221 b) 1403 c) 1249 d) 1337 e) 1179

Description : 53 × 47 + 64 × 56 -72 × 68 = ? a) 1221 b) 1403 c) 1249 d) 1337 e) 1179

Last Answer : Answer: e)

13 6 7 9 20 47.5 ? a) 149.5 b) 140.5 c) 150.5 d) 147.5 e) 145.5

Description : 13 6 7 9 20 47.5 ? a) 149.5 b) 140.5 c) 150.5 d) 147.5 e) 145.5

Last Answer : The series is × 0.5 – 0.5, × 1 + 1, ×1.5 – 1.5, ×2 + 2, ... Answer: e)

What is the ratio between money spent by company Q on tax and money spent by P on salary? a) 23:121 b) 33:144 c) 47:144 d) 144:157 e) None of these

Description : What is the ratio between money spent by company Q on tax and money spent by P on salary? a) 23:121 b) 33:144 c) 47:144 d) 144:157 e) None of these

Last Answer : e) None of these

The average weight of a group of 75 women was calculated as 47 kg. It was later discovered that the weight of one of the women was read as 45 kg, whereas her actual weight was 25kg. What is the actual average weight of the group of 75 women? (rounded off to two digits after decimal) (a) 46.73 kg (b) 46.64 kg (c) 45.96 kg (d) Cannot be determined (e) None of these

Description : The average weight of a group of 75 women was calculated as 47 kg. It was later discovered that the weight of one of the women was read as 45 kg, whereas her actual weight was 25kg. What is the actual average weight ... kg (b) 46.64 kg (c) 45.96 kg (d) Cannot be determined (e) None of these

Last Answer : (a) 46.73 kg

5287 – 176.22 – 78.584 = ? a) 5023.196 b) 5032.196 c) 5302.196 d) 5203.196 e) None of these

Description : 5287 – 176.22 – 78.584 = ? a) 5023.196 b) 5032.196 c) 5302.196 d) 5203.196 e) None of these

Last Answer : 5287 – 176.22 – 78.584 = 5032.196 Answer: b)

3, 9, 17, 27, 39, 53, ? a) 64 b) 69 c) 74 d) 78 e) 81

Description : 3, 9, 17, 27, 39, 53, ? a) 64 b) 69 c) 74 d) 78 e) 81

Last Answer : Series is 1× 2 + 1, 2 × 3 + 3, 3 × 4 + 5, 4 × 5 + 7, 5 × 6 + 9 Answer: b)

67,74,78,?,92,94 a) 86 b) 85 c) 83 d) 84 e) 88

Description : 67,74,78,?,92,94 a) 86 b) 85 c) 83 d) 84 e) 88

Last Answer : The next term is obtained by adding the unit’s digit to the number. Hence the missing number =78+8=86 Answer: a)

(37) 0.75 x [(7056) 0.25] ÷ (64) – 2 = (8) ? (Take 3 digits after the decimal point) a) 95.357 b) 69.567 c) 96.257 d) 78.584 e) 88.598

Description : (37) 0.75 x [(7056) 0.25] ÷ (64) – 2 = (8) ? (Take 3 digits after the decimal point) a) 95.357 b) 69.567 c) 96.257 d) 78.584 e) 88.598

Last Answer : (37) 0.75 x [(7056) 0.25] ÷ (64) – 2 = (8) ? Sol: 27.75 x 1764 ÷ 64 – 2 = 8 x ? 27.75 x 27.5625 – 2 = 8 x ? 762.859/8=? ? = 95.357 Answer: a)

19/14 x 12/72 x 18/29 x 767 = ? (Take 2 digits after the decimal point) a) 110.69 b) 118.78 c) 111.56 d) None e) 108.98

Description : 19/14 x 12/72 x 18/29 x 767 = ? (Take 2 digits after the decimal point) a) 110.69 b) 118.78 c) 111.56 d) None e) 108.98

Last Answer : 19/14 x 12/72 x 18/29 x 767 =? Sol: 1.35 x 0.16 x 0.62 x 767 = ? 102.71 = ? Answer: d)

(37÷44) + (78÷34) x (480÷85) = ? a) 11.769 b) 12.756 c) 13.796 d) 12.796 e) none

Description : (37÷44) + (78÷34) x (480÷85) = ? a) 11.769 b) 12.756 c) 13.796 d) 12.796 e) none

Last Answer : (37÷44) + (78÷34) x (480÷85) = ? Sol: 0.841 + 2.29412 x 5.64706 =? 0.841 + 12.955 =? ? = 13.796 Answer: c)

The average of weight of three men A,B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg.more than that of D, replaces A, then the average weight of B,C,D and E becomes 79 kg. The weight of A is : a) 70 kg b) 72 kg c) 75 kg d) 80 kg e) 78 kg

Description : The average of weight of three men A,B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg.more than that of D, replaces A, then the average weight of B,C ... 79 kg. The weight of A is : a) 70 kg b) 72 kg c) 75 kg d) 80 kg e) 78 kg

Last Answer : A+B+C = 3×84=252 A+B+C+D= (4×80)=320 D = (320-252)=68 and E = (68+3)=71 Now, B+C+D+E = (4×79)=316 B+C+D=(316-71)=245 kg So, A = (320-245)=75 kg Answer: c)

(37÷44) + (78÷34) x (480÷85) = ? a) 11.769 b) 12.756 c) 13.796 d) 12.796 e) none

Description : (37÷44) + (78÷34) x (480÷85) = ? a) 11.769 b) 12.756 c) 13.796 d) 12.796 e) none

Last Answer : (37÷44) + (78÷34) x (480÷85) = ? Sol: 0.841 + 2.29412 x 5.64706 =? 0.841 + 12.955 =? ? = 13.796 Answer: c)

The LCM of two numbers is 45 times their HCF. If one of the numbers is 125 and the sum of HCF and LCM is 1150, then the other number is? a) 100 b) 125 c) 250 d) 225 e) 180

Description : The LCM of two numbers is 45 times their HCF. If one of the numbers is 125 and the sum of HCF and LCM is 1150, then the other number is? a) 100 b) 125 c) 250 d) 225 e) 180

Last Answer : LCM = 45× HCF LCM + HCF = 46× HCF = 1150 HCF = 25, LCM =1125. product of 2 numbers = LCM×HCF required number = (25× 1125) / 125 = 225. Answer: d)

1 ? 27 64 125 a) 14 b) 4 c) 9 d) 8 e) None of these

Description : 1 ? 27 64 125 a) 14 b) 4 c) 9 d) 8 e) None of these

Last Answer : Answer: d)

520, 130, 32.5, 8.125, 2.03125,? a) 0.5087125 b) 0.5071875 c) 0.5012875 d) 0.5028125 e) 0.5078125

Description : 520, 130, 32.5, 8.125, 2.03125,? a) 0.5087125 b) 0.5071875 c) 0.5012875 d) 0.5028125 e) 0.5078125

Last Answer : The series is a geometric progression with common ratio 1/4 Hence the next term is 2.03125/4=0.5078125 Answer: e)

121 ? 113 138 89 170 49 a) 125 b) 110 c) 122 d) 120 e) 133

Description : 121 ? 113 138 89 170 49 a) 125 b) 110 c) 122 d) 120 e) 133

Last Answer : The series is +1^2 , -3^2 , +5^2 , - 7^2 , .... Answer: c)

185% of 400 + 35% of 240 = ?% of 1648 a) 85 b) 75 c) 125 d) 50 e) None of these

Description : 185% of 400 + 35% of 240 = ?% of 1648 a) 85 b) 75 c) 125 d) 50 e) None of these

Last Answer : 740 + 84 = 16.48 × ? 824 = 16.48 × ? ? = 50 Answer: d)

A train 125 m long passes a man, running at 5 kmph in the same direction in which the train is going, in 10 seconds. The speed of the train is: A.35 km/hr B.50 km/hr C.48 km/hr D.55 km/hr E.None of these

Description : A train 125 m long passes a man, running at 5 kmph in the same direction in which the train is going, in 10 seconds. The speed of the train is: A.35 km/hr B.50 km/hr C.48 km/hr D.55 km/hr E.None of these

Last Answer : Answer – B (50 km/hr) Explanation – Let speed be S Relative speed = total lengths/time [ in this case man length is neglible compare to train so neglected] (S – 5) x 5/18 = 125 /10 S- 5 = (125/10)x(18/5) S-5 = 45 S=50 km/hr

On an IQ test consisting of 250 questions, Jasvinder answered 40% of the first 125 questions correctly. What per cent of the other 125 questions does he need to answer correctly for his grade on the entire exam to be 60%? (a) 75% (b) 80% (c) 60% (d) Cannot be determined (e) None of these

Description : On an IQ test consisting of 250 questions, Jasvinder answered 40% of the first 125 questions correctly. What per cent of the other 125 questions does he need to answer correctly for his grade on the entire exam to be 60%? (a) 75% (b) 80% (c) 60% (d) Cannot be determined (e) None of these

Last Answer : (b) 80%

(54.78)^2= ? 1) 3000 2) 3300 3) 3500 4) 3700 5) 3900

Description : (54.78)^2= ? 1) 3000 2) 3300 3) 3500 4) 3700 5) 3900

Last Answer : 1) 3000

Convert each of the following fraction into a percentage: (i) 47 100 (ii) 9 20 (iii) 3 8 (iv) 8 125 (v) 19 500 (vi) 4 15 (vii) 2 3 (viii) 1 3 5 -Maths

Description : Convert each of the following fraction into a percentage: (i) 47 100 (ii) 9 20 (iii) 3 8 (iv) 8 125 (v) 19 500 (vi) 4 15 (vii) 2 3 (viii) 1 3 5 -Maths

Last Answer : We have the following: (i) 47100=47100×100% = 47% (ii) 920=920×100% =9×5%= 45% (iii) 38=38×100% =3×252%=752%=3712% (iv) 8125=8125×100%=8×45%=325%=6.4% (v) ... ;203%=803%=2623% (vii) 23=23×100%=2003%=6623% (viii) 135=85=85×100%=(8×20)%=160%

5, 13, 29, 61, 125, 253, _____ 1 : 512 2 : 521 3 : 509 4 : 552 5 : None of these

Description : 5, 13, 29, 61, 125, 253, _____ 1 : 512 2 : 521 3 : 509 4 : 552 5 : None of these

Last Answer : Answer-3(509) Explanation5 x2 +3 =13 13×2 +3=29 29×2+3=61 and so on..

A trader wants to sell a watch at 25% profit. If its cost price was Rs.x more, an extra profit of Rs.50 would be made on it. find x(in Rs.) a)100 b)125 c)150 d)200

Description : A trader wants to sell a watch at 25% profit. If its cost price was Rs.x more, an extra profit of Rs.50 would be made on it. find x(in Rs.) a)100 b)125 c)150 d)200

Last Answer : d)200

What is the total number of students enrolled in all the three classes together ? (1) 150 (2) 125 (3) 140 (4) 160 (5) None of these

Description : What is the total number of students enrolled in all the three classes together ? (1) 150 (2) 125 (3) 140 (4) 160 (5) None of these

Last Answer : (5) None of these

1 3 9 31 ? 651 a) 97 b) 127 c) 129 d) 109 e) None of these

Description : 1 3 9 31 ? 651 a) 97 b) 127 c) 129 d) 109 e) None of these

Last Answer : The series is ×1 + 2, ×2 + 3, ×3 + 4, ... Answer: c)

112 111 119 92 156 31 ? a) 375 b) 287 c) 387 d) 247 e) None of these

Description : 112 111 119 92 156 31 ? a) 375 b) 287 c) 387 d) 247 e) None of these

Last Answer : Answer: d)

(?)2 + (9.99)3 = (45.02)2 – (4.01)3 a) 34 b) 19 c) 26 d) 31 e) 12

Description : (?)2 + (9.99)3 = (45.02)2 – (4.01)3 a) 34 b) 19 c) 26 d) 31 e) 12

Last Answer : ?2 + 1000 = 2025 – 64 ?2 = 961  ? = 31 Answer: d)

8 1/4 ×5 2/3 – 4 1/6 × 4 1/5 = ? a) 31 b) 18 c) 14 d) 27 e) 23

Description : 8 1/4 ×5 2/3 – 4 1/6 × 4 1/5 = ? a) 31 b) 18 c) 14 d) 27 e) 23

Last Answer : ? = (33/4) × (27/5) – (25/6) × (21/5) =891/20 -35/2 ≈ 44.5 – 17.5 =27 Answer: d)

Ages of DEEPA and Subha are presently in the ratio of 5 : 6 respectively. Six years hence this ratio will become 6 : 7 respectively. What was Subha’s age 5 years ago? a) 33 years b) 32 years c) 35 years d) 31 years e) None of these

Description : Ages of DEEPA and Subha are presently in the ratio of 5 : 6 respectively. Six years hence this ratio will become 6 : 7 respectively. What was Subha’s age 5 years ago? a) 33 years b) 32 years c) 35 years d) 31 years e) None of these

Last Answer : Present ratio of Deepa&Subha = 5 : 6 Six year hence ratio of Deepa&Subha = 6 : 7 Difference between ratio = 1 Difference in ages between present & future = 6 year. 1 ratio=6 yrs & SUBHA's age = 6 6 =36 year 5 year ago ... = 7 6 = 42 year B's age 5 year ago = 42-6-5 = 42-11 = 31 year Answer: d)

On selling 25 balls at Rs. 1015, there is a profit equal to the cost price of 10 balls. What is the cost price of a ball? a) Rs. 31 b) Rs. 29 c) Rs. 35 d) Rs. 27 e) Rs. 39

Description : On selling 25 balls at Rs. 1015, there is a profit equal to the cost price of 10 balls. What is the cost price of a ball? a) Rs. 31 b) Rs. 29 c) Rs. 35 d) Rs. 27 e) Rs. 39

Last Answer : b Profit = (S.P of 25 balls) - (C.P of 25 balls) = 1015 - (C.P of 25 balls) Given that Profit = (C.P of 10 balls) => 1015 - (C.P of 25 balls) = (C.P of 10 balls) => (C.P of 25 balls) + (C.P of 10 balls) = 1015 => C.P of 35 balls = 1015 => C.P of 1 ball=1015 / 35 = Rs. 29

Vinoth could get equal number of Rs. 55, Rs. 85 and Rs. 105 ticket for a Zoo. He spend Rs. 3920 for all the tickets. How many of each did he buy? a) 15 b) 18 c) 16 d) 26 e) None of these

Description : Vinoth could get equal number of Rs. 55, Rs. 85 and Rs. 105 ticket for a Zoo. He spend Rs. 3920 for all the tickets. How many of each did he buy? a) 15 b) 18 c) 16 d) 26 e) None of these

Last Answer : Total money = 55x + 85x + 105x = 3920 245x = 3920 x = 16 Answer: c)

3 ? 113 673 3361 13441 40321 a) 13 b) 14 c) 15 d) 16 e) 17

Description : 3 ? 113 673 3361 13441 40321 a) 13 b) 14 c) 15 d) 16 e) 17

Last Answer : The series is: 3 × 8 – 7 = 17; 17 × 7 – 6 = 113; 113 × 6 – 5 = 673; 673 × 5 – 4 = 3361; 3361 × 4 – 3 = 13441; 13441 × 3 – 2 = 40321 Answer: e)

24 14 26 ? 28 16 30 a) 13 b) 17 c) 15 d) 11 e) 20

Description : 24 14 26 ? 28 16 30 a) 13 b) 17 c) 15 d) 11 e) 20

Last Answer : The series consists of two series 1 and 2: Series 1 : 24 26 28 30 +2 +2 +2 Series 2 : 14 15 16 +1 +1 Answer: c)

Present ages of A and B are 50 years and 18 years respectively. In how many years will A be twice as old as B? a) 14 years b) 15 years c) 16 years d) 18 years e) None of these

Description : Present ages of A and B are 50 years and 18 years respectively. In how many years will A be twice as old as B? a) 14 years b) 15 years c) 16 years d) 18 years e) None of these

Last Answer : Let the required time be x years. then (50+x) = 2 (18 + x) = 50 + x = 36 + 2x  x = 14 years. Alternative method : Double of B’s age = 2 × 18 = 36 years difference between A’s present age and double of B’s age = 50 – 36= 14 years. A will be twice of B’s age after 14 years. Answer: a)