Description : The ratio of the number of boys to that of girls in a school is 3:2. If 30% of boys and 70% of girls appeared in an examination, the ratio of students appeared in the examinations to that not appeared in the examination is A) 23:27 B) 22:25 C) 21:17 D) 18:17 E) None of these
Last Answer : Answer: A 3:2 = 30:20 30% boys = (30/100) × 30= 9 70% girls = (70/100) × 20 = 14 (9+14) : (50-23) = 23 : 27
Description : Class 12 | Maths | Complex Numbers | Simplify -2i ( 3 + i )( 2 + 4i )( 1 + i ) and obtain the modulus of that complex number.
Last Answer : Solution :
Description : A number is increased by 10% and the increased num\ber is decreased by 10%. Show that the net decrease is 1 -Maths
Last Answer : answer:
Description : Find the number whose 614% is 2. -Maths
Description : Find the number whose 13% is 65. -Maths
Description : Class 12 | Maths | Complex Numbers | Simplify the following complex numbers and find their modulus.
Last Answer : Class 12 | Maths | Complex Numbers | Simplify the following complex numbers and find their modulus.
Description : Maths | Complex Numbers | If √3 + i = r (cosθ + i sinθ), then find the value of θ in radian measure.
Description : Class 12 | Maths | Complex Numbers | Express the complex numbers modulus-amplitude form - √3 + i
Description : Fill in the blanks: (a) 1 lakh = ………….. ten thousand. (b) 1 million = …………… hundred thousand. (c) 1 crore = ………………. ten lakh. (d) 1 crore = ……………. million. (e) 1 million = ……………. lakh. -Maths
Last Answer : a) 10 (b) 10 (c) 10 (d) 10 (e) 10
Description : The population of a town increases at 5% per annum. Its present population is 16000. What will be its population after 2 years? -Maths
Description : The value of a machine depriciates at the rate of 10% per annum. If its present value is Rs 10000, what will be its value after 2 years? -Maths
Description : (i) What per cent of 1 kg is 125 g? (ii) What per cent of 80 m is 24 m? -Maths
Description : An ore contains 12% copper. How many kilograms of the ore are required to get 69 kg of copper? -Maths
Last Answer : 579 kg is the answer
Description : 96% of the cost of a TV is Rs 10464. What is its total cost? -Maths
Description : The excise duty on a certain item has been reduced to Rs 760 from Rs 950. Find the reduction per cent in the excise duy on that item. -Maths
Description : The monthly salary of a typist is Rs 15625. If he gets an increase of 12%, find his new salary. -Maths
Description : Rupesh secures 495 marks out of 750 in his annual examination. Find the percentage of marks obtained by him. -Maths
Description : What percentage is (i) Rs 15 of Rs 120? (ii) 36 minutes of 2 hours? (iii) 8 hours of 2 days (iv) 160 metres of 4 km? (v) 175 mL of 1 litre? (vi) 25 paise of Rs 4? -Maths
Description : What per cent of 84 is 14? -Maths
Description : If 12.5% of x is 6, find the value of x. -Maths
Description : What amount is 10% more than Rs 90? -Maths
Description : Find: (i) 25% of Rs 76 (ii) 20% of Rs 132 (iii) 7.5% of 600 m (iv) 313% of 90 km (v) 8.5% of 5 kg (vi) 20% of 12 litres -Maths
Description : Find: (i) 32% of 425 (ii) 1623% of 16 (iii) 6.5% of 400 (iv) 136% of 70 (v) 2.8% of 35 (vi) 0.6% of 45 -Maths
Description : Convert each of the following decimals into a percentage: (i) 0.6 (ii) 0.42 (iii) 0.07 (iv) 0.005 -Maths
Description : Convert each of the following into decimal form: (i) 45% (ii) 127% (iii) 3.6% (iv) 0.23% -Maths
Description : Convert each of the following ratios into a percentage: (i) 37 : 100 (ii) 16 : 25 (iii) 3 : 5 (iv) 5 : 4 -Maths
Description : Express each of the following as a ratio: (i) 43% (ii) 36% (iii) 7.5% (iv) 125% -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%
Description : Convert each of the following into a fraction: (i) 32% (ii) 614% (iii) 2623% (iv) 120% (v) 6.25% (vi) 0.8% (vii) 0.06% (viii) 22.75% -Maths
Description : Write each of the following as decimals: (a) 5 / 10 (b) 3 + 7 / 10 (c) 200 + 60 + 5 + 1 / 10 (d) 70 + 8 / 10 (e) 88 / 10 -Maths
Last Answer : (a) 5 / 10 = 0.5 (b) 3 + 7 / 10 = 3 + 0.7 = 3.7 (c) 200 + 60 + 5 + 1 / 10 = 265 + 0.1 = 265.1 (d) 70 + 8 / 10 = 70 + 0.8 = 70.8 (e) 88 / 10 = 80 / 10 + 8 / 10 = 8 + 0.8 = 8.8 (f) (g) 3 / 2 = (2 + 1) / ... + 0.5 = 1.5 (h) 2 / 5 = 0.4 (i) 12 / 5 = (10 + 2) / 5 = 10 / 5 + 2 / 5 = 2 + 0.4 = 2.4 (j) (k)
Description : Write each of the following as decimals: (a) Seven-tenths (b) Two tens and nine-tenths (c) Fourteen point six (d) One hundred and two ones (e) Six hundred point eight -Maths
Last Answer : (a) The decimal form of Seven-tenths is 7 / 10 = 0.7 (b) The decimal form of two tens and nine tenths is 20 + 9 / 10 = 20.9 (c) The decimal form of fourteen point six is 14.6 (d) The decimal form of one hundred and two ones is 100 + 2 = 102.0 (e) The decimal form of six hundred point eight is 600.8
Description : The ratio of the number of boys to the number of girls in a school is 6 : 5. If 20% of boys and 45% of girls come by bus to school, what percentage of students opt transport other than bus to come to school? A) 68 9/11% B) 68 7/11% C) 72 7/11% D) 73% E) 73 5/11%
Last Answer : Answer: B If 20% of boys and 45% of girls come by bus, then 80% of boys and 55% of girls opt transport other than bus. Let total number of students in school = x So boys who opt other transport are (80/100) * 6/(6+5 ... (24x/55) + (x/4) = 151x/220 So required % = [(151x/220)/x] * 100 = 68 7/11 %
Description : The ratio of girls and boys in a class is 1: 3. Set up an equation between the students of a class and boys and then draw its graph. Also find the number of boys in a class of 40 students from the graph. -Maths 9th
Last Answer : Total number of boys and girl = 40, Ratio = 1 : 3 Number of girls be A and Number of boys be B. Ratio of number of girls and boys is 1 : 3, so Therefore 3A=B To find number of boys we ... the number 30 represents the number of girls. 40 as total on the line A = 10, which is the common equation.
Description : A class consists of 80 students, 25 of them are girls and 55 boys. 10 of them are rich and 20 are fair complexioned. -Maths 9th
Last Answer : Let P (A) = Probability of selecting a fair complexioned person. ThenP(A) = \(rac{20}{80}\) = \(rac{1}{4}\)Let P(B) = Probability of selecting a rich person. Then P(B) = \(rac{10}{80}\) = \(rac{1}{8}\)Let P (C) = ... ) = \(rac{1}{4}\)x \(rac{1}{8}\)x \(rac{5}{16}\) = \(rac{5}{512}\) = 0.009.
Description : A school has 9 maths teachers and 6 science teachers. In how many ways can a team of 4 maths teachers be formed from them such that the team must contain exactly 1 science teacher? A) 800 B) 720 C) 680 D) 504
Last Answer : Answer: D) The team should have 4 maths teachers. But the team must contain exactly 1 science teacher. Hence, select 3 maths teachers from 9 maths teachers and select 1 science teachers from 6 science teachers. Number of ways this can be ... ={9 8 7}/{3 2 1}X6 = 504 / 6 6 = 84 6 =504
Description : The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ratio of the number of boys to the number of girls in the class is: A. 1 : 4 B. 2 : 3 C. 3 : 4 D. 4 : 2 E. None of these
Last Answer : Answer – B (2 : 3) Explanation – Let the ratio be k:1 Then, k x 16.4 + 1 x 15.4 = (k + 1) x 15.8 (16.4 – 15.8) k = (15.8 – 15.4) k=2/3
Description : Out of the students studying Homeopathy, what is the ratio between number of boys knowing English and the number of girls knowing Hindi respectively? (1) 3 : 5 (2) 2 : 3 (3) 9 : 11
Last Answer : (2) 2 : 3
Description : Number of students in 4th and 5th class is in the ratio 6 : 11. 40% in class 4 are girls and 48% in class 5 are girls. What percentage of students in both the classes are boys? A) 62.5% B) 54.8% C) 52.6% D) 55.8% E) 53.5%
Last Answer : Answer: B Total students in both = 6x+11x = 17x Boys in class 4 = (60/100)*6x = 360x/100 Boys in class 5 = (52/100)*11x = 572x/100 So total boys = 360x/100 + 572x/100 = 932x/100 = 9.32x % of boys = [9.32x/17x] * 100=54.8%
Description : The average age of students of a college is 31.6 yrs. The average age of boys in the class is 32.8 yrs and that of girls is 30.8. The ratio of number of boys to the number of girls in the class. A) 2:3 B) 3:1 C) 1:3 D) 3:2
Last Answer : A) Let the ratio be D:1.then, (D * 32.8) + ( 1* 30.8)= (D+1) * 31.6 32.8 D +30.8 = 31.6 D + 31.6 32.8 D – 31.6D = 31.6 – 30.8 1.2D = 0.8 D = 0.8/1/2 = 0.4/0.6 D = 2/3 Required ratio = 2/3 :1 = 2:3.
Description : In a college of 1335 students, 60 % are boys. Find the number of girls and number of boys in the college? a) 924,221 b) 691,404 c) 802,333 d) 441,564 e) 534,801
Last Answer : Answer: E Number of boys in the college = 60 % of 1335 = 60/100 × 1335 = 80100/100 = 801 Number of girls in the college = Total number of students in the college - Number of boys = 1335 – 801 =534
Description : there are 24 students in a class 8 of the student are boys a) write the amount of boys in the class as a fraction in its simplest form b) write the amount of girls in the class as a fraction in its simplest form?
Last Answer : two thirds
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)
Description : In a batch, there are 22 boys and 18 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is: a) 3754/8854 b) 4158/9880 c) 8514/9880 d) 2078/4920
Last Answer : Answer: B) Let , S - sample space E - event of selecting 1 girl and 2 boys. Then, n(S) = Number ways of selecting 3 students out of 40 = 40C3 = 9880 n(E) = 18C1 *22C2 = 18*231 = 4158 P(E) = n(E)/n(s) = 4158/9880
Description : If `20%` of the student in a school are girls and the number of boys is 3060, then find the total strength of the school.
Last Answer : If `20%` of the student in a school are girls and the number of boys is 3060, then find the total strength of the school.
Description : The ratio between the number of boys and girls in a school is 4:5. If the number of boys are increased by 30 % and the number of girls increased by 40 %, then what will the new ratio of boys and girls in the school. A) 13/35 B) 26/35 C) 26/41 D) 23/13 E) None of these
Last Answer : Answer: B boys = 4x and girls = 5x. Required ratio = [(130/100)*4x]/ [(140/100)*5x] 26/35
Description : Is it ok for 2 fifteen year old girls to travel to a high school soccer game on the same bus with 40 teenage boys and two male coaches?
Last Answer : Why not offer to function as a chaperone? I’m sure the school would appreciate a volunteer.
Description : Regarding co-education at the secondary stage, the 1952-53 Education Commission has suggested that Options: A) To start, resource, in several states could not afford B) There should be ... D) The situation in our country warrants establishment of more boys schools than co-educational school.
Last Answer : A) To start, resource, in several states could not afford
Description : In a class, there are x girls and y boys, a student is selected at random, then find the probability of selecting a boy. -Maths 9th
Last Answer : Number of boys = y Total students = (x + y) Thus,P(a boy)= y/(x+y)
Description : Four boys and three girls stand in a queue for an interview. What is the probability that they will be in alternate positions ? -Maths 9th
Last Answer : Total number of ways of arranging 4 boys and 3 girls, i.e., 7 people in a queue (row) = n(S) = 7! Let A : Event in which the 4 boys and 3 girls occupy alternate position. This is possible when the ... {4 imes3 imes2 imes1 imes3 imes2 imes1}{7 imes6 imes5 imes4 imes3 imes2 imes1}\) = \(rac{1}{35}.\)