UPSC Civil Services 2019 Prelims General Studies Paper II

A number is divisible by '3' if sum of its digits be divisible by 3.
Here, Given number is 4252746 B
Sum of its digits = 4 + 2+ 5 + 2 + 7 + 4 + 6 + B
= 30 + B.
For, B = 0, 3, 6, 9;
Sum of digits will be divisible by '3'.
Hence, number of values of B = 4.