The average amount of money collected by a group of students at a flag day event was $102. When another 13 students turned up to help, the total amount donated increased by $714 and the average amount of money collected became $84. 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 + 13 |
| Value |
102 |
84 |
| Total Value |
102 u + 714 |
84 u + 1092 |
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
= 84 x (1 u + 13)
= 84 u + 1092
102 u + 714 = 84 u + 1092
102 u - 84 u = 1092 - 714
18 u = 378
1 u = 378 ÷ 18 = 21
Number of students in the end
= 1 u + 13
= 21 + 13
= 34
Answer(s): 34
