Question

216 - 1 is divisible by
(a) 11 (b) 13
(c) 17
(d) 19
​

Answer 1

Answer:

c) 17

Step-by-step explanation:

2^16 -1 = (2^8) 2-1

= (2^8 +1) (2^8-1)

= (256+1) ( 256-1)

= 257× 255 which is exactly divisible by 17