The average amount of money collected by a group of pupils at a flag day event was $104. When another 12 pupils turned up to help, the total amount donated increased by $656 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 + 12 |
Value |
104 |
88 |
Total Value |
104 u + 656 |
88 u + 1056 |
Number of pupils at first = 1 u
Total amount collected by the pupils at first
= 1 u x 104
= 104 u
Total amount collected by the pupils in the end
= 88 x (1 u + 12)
= 88 u + 1056
104 u + 656 = 88 u + 1056
104 u - 88 u = 1056 - 656
16 u = 400
1 u = 400 ÷ 16 = 25
Number of pupils at first
= 1 u
= 25
Answer(s): 25