Question

If 21 y 5 is a multiple of 9 where Y is a digit what is the value of Y

Answer 1

Answer:

Any number which is divisible by 9 then the sum of the digits of the number is also divisible by 9 so (2+1+Y+5) should be divisible by 9 and Y lies between 0 and 9. Hence (Y+8)=9,18,... =>Y+8=9 =>Y=1 but if Y+8=18 =>Y=10 but it is not possible. Hence the value of Y is 1. Hope it helps you.

Answer 2

Step-by-step explanation:

1. 21y5 is divisible by 9 so, the sum of it's digit is 2+1+y+5=8+y should be divisible by 9
2. 2+1+y+5=9
3. 8+y=9
4. Y=9-8
5. Y=1