If is a number with x as its tens digit such that it is divisible by 4. Find all possible values of x.
Here, given number is divisible by 4
We know that a number is divisible by 4, only when the number formed by its digits in units and tens place is divisible by 4.
∴ x2 is divisible by 4
Expanding x2,
10x + 2 = multiple of 4
Now, x2 can take values 2, 12, 22, 32, 42, 52, 62, 72, 82, 92
Out of these only 12, 32, 52, 72 and 92
∴ x can take values 1,3,5,7 and 9