Question

If 21y5 is a multiple of 9, where y is a digit, what is the value of y?​

Answer 1

Answer : y = 1

Step-by-step explanation:

21y5 is a multiple of 9.

So, sum of 21y5 should be a multiple of 9.

2+1+y+5=8+y

let 8+y= 9

Therefore , y=9-8=1

Answer 2

If 21y5 is a multiple of 9, where y is a digit, what is the value of y?