Question
If 45780x52 is divisible by 72, then find the sum of all
possible values of 'x'.Solution
72 = 8 X 9 So, the given number must be divisible by both 8 and 9. If the given number is divisible by 8, then x52 is divisible by 8 So, possible values of 'x' are 1, 3, 5 and 7. If the given number is divisible by 9, then sum of the digits must be divisible by 9, So, 4 + 5 + 7 + 8 + 0 + x + 5 + 2 = (31 + x) must be divisible by 9 So, only possible value of x is 5 So, required sum = 5
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