CAT 1995 — QA Question 2
FactorsEasy
56 - 1 is divisible by
Answer & solution
- A
13
31
- C
5
- D
None of these
Solution
56 – 1 = (53)2 – 1 = (125)2 – (1)2 = (125 + 1) (125 – 1) = 124 × 126 = 31 × 4 × 126.
So among the given answer choices, it is divisible by 31.