The average test score of a class was 66 marks. After five students who scored an average marks of 96 marks transferred out of the class, the average score of the remaining students became 60 marks. How many students were there in the class in the end?
|
(1) |
(2) |
Number |
1 u |
1 u - 5 |
Value |
66 |
60 |
Total value |
66 u |
60 u - 300 |
Number of students at first = 1 u
Total score at first
= 1 u x 66
= 66 u
Total score of the 5 students
= 5 x 96
= 480
Total marks scored after 5 students transferred out
= 60 x (1 u - 5)
= 60 u - 300
66 u - 480 = 60 u - 300
66 u - 60 u = 480 - 300
6 u = 180
1 u = 180 ÷ 6 = 30
Number of students in the class in the end
= 1 u - 5
= 30 - 5
= 25
Answer(s): 25