Question

If x and y are the two digits of the number 653xy such that this number is divisible by 80 then x+y=

Answer 1

Thr number is 65360

1) Since the number is exactly divisible by 80, then it is also divisible by 10.

2) Hence the last digit of the number must be 0.

3) Now, the number becomes 653x0.

4) Dividing the number by 80

653x0/80 or 653x/8

5) Hence the number 653x must be divisible by 8.

6) The divisibility test for 8 is that the last 3 digits of number must be divisible by 8.

7) Last 3 digits are 53x, the only number that satisfies this condition is 6.

8) Hence the number is 65360