The average test score of a class was 70 marks. After three students who scored an average marks of 94 marks transferred out of the class, the average score of the remaining students became 61 marks. How many students were there in the class in the end?
| |
(1) |
(2) |
| Number |
1 u |
1 u - 3 |
| Value |
70 |
61 |
| Total value |
70 u |
61 u - 183 |
Number of students at first = 1 u
Total score at first
= 1 u x 70
= 70 u
Total score of the 3 students
= 3 x 94
= 282
Total marks scored after 3 students transferred out
= 61 x (1 u - 3)
= 61 u - 183
70 u - 282 = 61 u - 183
70 u - 61 u = 282 - 183
9 u = 99
1 u = 99 ÷ 9 = 11
Number of students in the class in the end
= 1 u - 3
= 11 - 3
= 8
Answer(s): 8
