The average amount of money collected by a group of students at a flag day event was $112. When another 15 students turned up to help, the total amount donated increased by $822 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 |
112 |
79 |
| Total Value |
112 u + 822 |
79 u + 1185 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 112
= 112 u
Total amount collected by the students in the end
= 79 x (1 u + 15)
= 79 u + 1185
112 u + 822 = 79 u + 1185
112 u - 79 u = 1185 - 822
33 u = 363
1 u = 363 ÷ 33 = 11
Number of students in the end
= 1 u + 15
= 11 + 15
= 26
Answer(s): 26
