Question

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

Answer 1

Step-by-step explanation:

The sum of its digits = 2 + 1 + y + 5 = 8 + y is a multiple of 9

• Here, 8 + y is either 0 or 9 or 18

8 + y = 9

y = 9 - 8

y = 1