The average test score of a class was 67 marks. After four students who scored an average marks of 94 marks transferred out of the class, the average score of the remaining students became 64 marks. How many students were there in the class in the end?
|
(1) |
(2) |
Number |
1 u |
1 u - 4 |
Value |
67 |
64 |
Total value |
67 u |
64 u - 256 |
Number of students at first = 1 u
Total score at first
= 1 u x 67
= 67 u
Total score of the 4 students
= 4 x 94
= 376
Total marks scored after 4 students transferred out
= 64 x (1 u - 4)
= 64 u - 256
67 u - 376 = 64 u - 256
67 u - 64 u = 376 - 256
3 u = 120
1 u = 120 ÷ 3 = 40
Number of students in the class in the end
= 1 u - 4
= 40 - 4
= 36
Answer(s): 36