Question

For what value of b 83b49 is divisible by 3.

Answer 1

from divisibility test, if a number is divisible by 3 then sum of its digits must be divisible by 3.
8+3+b+4+9=b+24
so for b=0,3,6,9. 83b49 is divisible by 3.

Answer 2

The value of b is 0.It can also be any multiple of 3.