Question

Find the value of b for which the number 3215b2’ is divisible by 3?

Answer 1

Answer:

2, 5 or 8

Step-by-step explanation:

Divisibility rule of 3 = sum of digits of the number is divisible by three or not

Sum of digits of the number (except b) = 3 + 2 + 1 + 5 + 2 = 13

to make it divisible by 3, find the number greater than the sum of digits of the number but divisible by 3 and subtract both numbers..

15 > 13 so, 15 - 13 = 2

18 > 13 so, 18 - 13 = 5

21 > 13 so, 21 - 13 = 8

24 > 13 so, 24 - 13 = 11 (but it should not exceed 9)

∵b can be filled by 2, 5 or 8