The number of pairs of positive integers whose sum is 99 and HCF is 9 is = ?

A. 5

B. 2

C. 3

D. 4

Answer: Option A

Solution(By Examveda Team)

According to question,
HCF = 9
⇒ Then the two number will be 9a, 9b
⇒ 9a + 9b = 99
⇒ a + b = 11
⇒ Pairs of positive integer (1, 10) (2, 9) (3, 8) (4, 7) (5, 6) = 5