The average amount of money collected by a group of students at a flag day event was $102. When another 11 students turned up to help, the total amount donated increased by $597 and the average amount of money collected became $87. How many students were there in the group in the end?
|
Number of students at first |
Number of students in the end |
Number |
1 u |
1 u + 11 |
Value |
102 |
87 |
Total Value |
102 u + 597 |
87 u + 957 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 102
= 102 u
Total amount collected by the students in the end
= 87 x (1 u + 11)
= 87 u + 957
102 u + 597 = 87 u + 957
102 u - 87 u = 957 - 597
15 u = 360
1 u = 360 ÷ 15 = 24
Number of students in the end
= 1 u + 11
= 24 + 11
= 35
Answer(s): 35