UPSC Prelims 2019·CSAT·Quantitative Aptitude·Number System

An 8-digit number 4252746B leaves remainder 0 when divided by 3. How many values of B are possible?

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Last updated 8 Jul 2026, 4:39 pm IST
  1. A2
  2. B3
  3. C4Correct
  4. D6

Explanation

A number is divisible by 3 if the sum of its digits is divisible by 3.

For the number 4252746B, the sum of its digits is: 4 + 2 + 5 + 2 + 7 + 4 + 6 + B = 30 + B

Since the number leaves remainder 0 when divided by 3, (30 + B) must be divisible by 3. As 30 is already divisible by 3, B must also be divisible by 3 for the entire sum to be divisible by 3.

B is a single digit, so its possible values range from 0 to 9. The values of B in this range that are divisible by 3 are: 0 (30+0 = 30, divisible by 3) 3 (30+3 = 33, divisible by 3) 6 (30+6 = 36, divisible by 3) 9 (30+9 = 39, divisible by 3)

There are 4 possible values for B.

The final answer is C) 4.

Quantitative Aptitude: An 8-digit number 4252746B leaves remainder 0 when divided by 3. How many values of B are possible?

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