The average amount of money collected by a group of pupils at a flag day event was $104. When another 10 pupils turned up to help, the total amount donated increased by $512 and the average amount of money collected became $88. How many pupils were there in the group in the end?
|
Number of pupils at first |
Number of pupils in the end |
Number |
1 u |
1 u + 10 |
Value |
104 |
88 |
Total Value |
104 u + 512 |
88 u + 880 |
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 + 10)
= 88 u + 880
104 u + 512 = 88 u + 880
104 u - 88 u = 880 - 512
16 u = 368
1 u = 368 ÷ 16 = 23
Number of pupils in the end
= 1 u + 10
= 23 + 10
= 33
Answer(s): 33