The sum of 2 numbers is 216, and their HCF is 27. How many such pairs of numbers exist? (A pair a unique set of 2 numbers, so (a, b) and (b, a) will be considered as 1 pair).
a) 0
b) 1
c) 2
d) 3
e) 4
Let the numbers be a,b
A = 27m, b = 27n where m, n are co-prime
27(m + n) = 216, or m+n = 8
M = 1, n = 7 and m = 3, n = 5 are the only 2 co – prime pairs possible.
So we have 2 pairs: (27 , 189) and ( 81, 135)
Answer: c)