The average amount of money collected by a group of students at a flag day event was $116. When another 15 students turned up to help, the total amount donated increased by $852 and the average amount of money collected became $79. 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 + 15 |
Value |
116 |
79 |
Total Value |
116 u + 852 |
79 u + 1185 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 116
= 116 u
Total amount collected by the students in the end
= 79 x (1 u + 15)
= 79 u + 1185
116 u + 852 = 79 u + 1185
116 u - 79 u = 1185 - 852
37 u = 333
1 u = 333 ÷ 37 = 9
Number of students in the end
= 1 u + 15
= 9 + 15
= 24
Answer(s): 24