Question

21y5 is a multiple of 3 then value of y is=

Answer 1

since 21y5 is a multiple of 3 then the Sum of digits will be divisible by 3,

then

sum of digits=2+1+y+5,

=8+y,

so it's clear then minimum value of y should be 1 so that sum of the digits become 9 and which is divisible by 3