The average test score of a class was 65 marks. After three students who scored an average marks of 95 marks transferred out of the class, the average score of the remaining students became 56 marks. How many students were there in the class in the end?
|
(1) |
(2) |
Number |
1 u |
1 u - 3 |
Value |
65 |
56 |
Total value |
65 u |
56 u - 168 |
Number of students at first = 1 u
Total score at first
= 1 u x 65
= 65 u
Total score of the 3 students
= 3 x 95
= 285
Total marks scored after 3 students transferred out
= 56 x (1 u - 3)
= 56 u - 168
65 u - 285 = 56 u - 168
65 u - 56 u = 285 - 168
9 u = 117
1 u = 117 ÷ 9 = 13
Number of students in the class in the end
= 1 u - 3
= 13 - 3
= 10
Answer(s): 10