. If 21y5 is multiple of 9 where y is a digit what is the value of y
We know that if a number is divisible by 9, then the sum of digits of that number is either 0 or a multiple of 9.
Here given that, 21y5 is divisible by 9
Then the sum of the digits of given number =2+1+y+5=8+y
Since y is a digits then it can be =0,1,2,3,4,5,6,7,8, or 9
The value of y in the number 21y5 is 1.