Question

A group of students takes a test and the average score is 72. One more student takes the test and receives a score of 88 increasing the average score of the group to 76. How many students were in the initial group

Answer 1

3 student.

Explanation:

From the first statement:

Let the total score be T

Let the total number of student be x

The average of the score = 72

Average = Tota score / number of student

72 = T/x

Cross multiply

T = 72x ..... (1)

Second statement:

One more student took the test and the average becomes 76 with the student having a score of 88.

Therefore,

Overall score = T + 88

Total student = x + 1

Average = 76

Average = overall score / total number of student

76 = (T + 88) /(x + 1)

Cross multiply

76(x + 1) = T + 88

Clear bracket

76x + 76 = T + 88

From equation 1

T = 72x

76x + 76 = 72x + 88

Collect like terms

76x – 72x = 88 – 76

4x = 12

Divide both side by the coefficient of x i.e 4

x = 12/4

x = 3

Therefore, the initial number of the student were 3.