Question

3241x3 is divisible by 9 : find the value of X

Answer 1

By divisibility rule.... 9 | (3+2+4+1+x+3)   ---> If 9 divides a no., then 9 divides the sum of digits......
=> 9 | ( 13+x )
=> 9 | 9 + 4 + x
=> 9 | 4 + x
=> the value of x can be -4 or 5...
But since, x is a digit, x = 5 is the only possible soln.
Hope you are satisfied with the answer.......... 

Answer 2

3+2+4+1+x+3 = 13+x
now x = 5
because 18 is divisible by 9