SSC CPO 2022 PYQ — Question 131

The correct answer is Option 2 i.e. $2 \frac{1}{10}$.

Given that

If the 9-digit number 72x8431y4 is divisible by 36,

We know that,

If a number is divisible by 36 then it must be divisible by 4 and 9 as well.

Divisibility test of 4 = Last two digits should be divisible by 4.

Divisibility test of 9 = Sum of all digits should be divisible by 9.

Now,

For the divisibility of the last two digits by 4, the smallest possible value of y = 2

Now, the sum of the digits of the given numbers = 7 + 2 + x + 8 + 4 + 3 + 1 + 2 + 4 = 31 + x

For divisible by the value of x be 5

Hence,  the value of $\left(\frac{x}{y}-\frac{y}{x}\right)$ = (5/2) - (2/5) = (25 - 4)/10 = 21/10 = $2 \frac{1}{10}$