The average amount of money collected by a group of students at a flag day event was $100. When another 11 students turned up to help, the total amount donated increased by $658 and the average amount of money collected became $83. 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 |
100 |
83 |
| Total Value |
100 u + 658 |
83 u + 913 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 100
= 100 u
Total amount collected by the students in the end
= 83 x (1 u + 11)
= 83 u + 913
100 u + 658 = 83 u + 913
100 u - 83 u = 913 - 658
17 u = 255
1 u = 255 ÷ 17 = 15
Number of students in the end
= 1 u + 11
= 15 + 11
= 26
Answer(s): 26
