The number of boys in a class is three times the number of girls. Which one of the following numbers cannot represent the total number of student in the class?

A 48

B 44

C 42

D 40

Correct Answer: Option C

12+12*3 = 12 + 36 = 48

11 + 11*3 = 11 + 33 = 44

10 + 10*3 = 10 + 30 = 40

Let number of girls = x and number of boys = 3x.

Then, 3x + x = 4x = total number of students.

Thus, to find exact value of x, the total number of students must be divisible by 4.