If x and y are digits such that 17!=3556xy428096000, then x+y equals
Given, 17!=3556xy428096000
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 multiply of 11 or 0. The only possibility is |x−y|=1
∴x+y=15