Question

1/6 of the class students are above average, 1/4 are average and rest are below average. If there are 48 students in all, how many students are below average in the class?

Answer 1

total no . of students who are below average =  1-1/6+1/4
                                                                = 1-5/12
                                                                 = 7/12
       no . of students who are below average = 7/12×48
                                                                 ⇒ 28 .

Answer 2

Given - Number of students

Find - Students below average

Solution - The fraction of students below average in the class are = $1 - ( \frac{1}{6} + \frac{1}{4} )$

Taking LCM of fraction inside bracket, we get 12. Solving to find the fraction of students below average.

Students below average = $1 - ( \frac{(1 \times 2) + (1 \times 3)}{12} )$

Students below average = $1 - ( \frac{2 + 3}{12} )$

Students below average = $1 - \frac{5}{12}$

Again taking LCM, we get 12. Solving to find fraction of students below average.

Students below average = $\frac{12 - 5}{12}$

Performing subtraction

Students below average = $\frac{7}{12}$

Now, number of students below average = $\frac{7}{12} \times 48$

Performing division

Number of students below average = $7 \times 4$

Performing multiplication

Number of students below average = 28.

Hence, there are 28 students below average in the class.