216 - 1 is divisible by
11
13
17
19
C.
17
216 - 1 = (28)2 - 1
= (28 + 1) (28 - 1)
= (256 + 1) (256 - 1)
= 257 x 255 which is exactly divisible by 17.
A certain number, when divided by 899, leaves the remainder 65. When the same number is divided by 31, the remainder is
3
4
1
2
A number x, when divided by 289 leaves 18 as the remainder. The same number when divided by 17 leaves y as a remainder. The value of y is
2
3
1
5
The fifth term of the sequence for which t1 = 1, t2 = 2 and tn+2 = tn + tn+1 is
5
10
6
8
If X and Y are the two digits of the number 347XY such that the number is completely divisible by 80, then what is the value of X + Y?
2
4
6
8