Question

If 98215x2 is divisible by 4.Then find all values of x.

Answer 1

If the no. formed by the last two digits of a number is divisible by 4, then so will be that number.

100x + 10y + z will be divisible by 4 if 10y + z is divisible by 4, for any positive integer x and for any one-digit positive integers y and z.

If 98215x2 is divisible by 4, then so will be x2.

Two digits multiples of 4 ending in 2 are:  12, 32, 52, 72, 92.

Thus the possible values of x are 1, 3, 5, 7 and 9.