The average test score of a class was 61 marks. After five 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 at first?
|
(1) |
(2) |
Number |
1 u |
1 u - 5 |
Value |
61 |
56 |
Total value |
61 u |
56 u - 280 |
Number of students at first = 1 u
Total score at first
= 1 u x 61
= 61 u
Total score of the 5 students
= 5 x 95
= 475
Total marks scored after 5 students transferred out
= 56 x (1 u - 5)
= 56 u - 280
61 u - 475 = 56 u - 280
61 u - 56 u = 475 - 280
5 u = 195
1 u = 195 ÷ 5 = 39
Number of students in the class at first
= 1 u
= 39
Answer(s): 39