WBJEE 2015 Math Solved Paper

Since 17! is divisible by 9 so sum of the digits 48 + x + y must be divisible by 9.So, x + y can be 15 or 6.
Also 17! is divisible by 11 so |10 + x – y| must be multiple of 11 or zero. The only possibility is |x – y| = 1So, x + y = 15