The average amount of money collected by a group of pupils at a flag day event was $100. When another 14 pupils turned up to help, the total amount donated increased by $504 and the average amount of money collected became $84. 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 + 14 |
Value |
100 |
84 |
Total Value |
100 u + 504 |
84 u + 1176 |
Number of pupils at first = 1 u
Total amount collected by the pupils at first
= 1 u x 100
= 100 u
Total amount collected by the pupils in the end
= 84 x (1 u + 14)
= 84 u + 1176
100 u + 504 = 84 u + 1176
100 u - 84 u = 1176 - 504
16 u = 672
1 u = 672 ÷ 16 = 42
Number of pupils in the end
= 1 u + 14
= 42 + 14
= 56
Answer(s): 56