Question

find a and b so that the following odd numbers are divisible by both 3 and 5 8ab4b ​

Answer 1

(i)7b25

It is divisible by 5.

For it to be divisible by 3, 5+b must be divisible by 3.

Therefore, b=1,4,7

(ii)8ab4b

For the number to be odd and divisible by 5, b=5

Now, for it to be divisible by 3, 4+a must be divisible by 3.

Therefore, a=2,5,8