The average amount of money collected by a group of pupils at a flag day event was $111. When another 14 pupils turned up to help, the total amount donated increased by $657 and the average amount of money collected became $88. How many pupils were there in the group at first?
|
Number of pupils at first |
Number of pupils in the end |
Number |
1 u |
1 u + 14 |
Value |
111 |
88 |
Total Value |
111 u + 657 |
88 u + 1232 |
Number of pupils at first = 1 u
Total amount collected by the pupils at first
= 1 u x 111
= 111 u
Total amount collected by the pupils in the end
= 88 x (1 u + 14)
= 88 u + 1232
111 u + 657 = 88 u + 1232
111 u - 88 u = 1232 - 657
23 u = 575
1 u = 575 ÷ 23 = 25
Number of pupils at first
= 1 u
= 25
Answer(s): 25