Question

21Y5 is a multiple of 9,where Y is a digit, what is the value of Y? give in brief
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Answer 1

Answer:

In the given problem 21y5 is multiple of 9. This means 21y5 is divisible by 9. So, the sum of the digits of 21y5 has to be divisible by 9. This means 2+1+y+5=y+8 is divisible by 9.

For example: 8 + y = 9

⇒y = 9 − 8 = 1