The number (248 - 1) is exactly divisible by two numbers between 60 and 70. The numbers are :
A. 63 and 65
B. 63 and 67
C. 61 and 65
D. 65 and 67
Answer: Option A
Solution (By Examveda Team)
(248 - 1)= [(26)8 - 1]
= (64)8 - 1
When n is even , (xn - an) is completely divisible by both (x - a) and (x + a)
∴ (648 - 18) is divisible by both (64 - 1) and (64 + 1)
⇒ (248 - 1) is divisible by both 63 and 65
This Question Belongs to Arithmetic Ability >> Number System
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