Three friends divided some bullets equally. After each of them shot 4 bullets, the total number of bullets remaining is equal to the bullets each had after division. Find the original number of bullets:

Options

A. 15
B. 17
C. 20
D. 18

Answer

D

Explanation

Let the original number of bullets = x
Then, each of them had `x/3` bullets after division.
So, total number of bullets they had after using 4 bullets each
`= (x/3 - 4) + (x/3 – 4) +(x/3 - 4) = x – 12`
According to the question `x - 12 = x/3`
or, `x - x/3 =12 `
or, `(3x – x)/3 = 12` or, `2x = 36` or, `x = 18`.
Therefore, the original number of bullets = `x = 18`.