The average amount of money collected by a group of pupils at a flag day event was $103. When another 14 pupils turned up to help, the total amount donated increased by $644 and the average amount of money collected became $82. 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 |
103 |
82 |
Total Value |
103 u + 644 |
82 u + 1148 |
Number of pupils at first = 1 u
Total amount collected by the pupils at first
= 1 u x 103
= 103 u
Total amount collected by the pupils in the end
= 82 x (1 u + 14)
= 82 u + 1148
103 u + 644 = 82 u + 1148
103 u - 82 u = 1148 - 644
21 u = 504
1 u = 504 ÷ 21 = 24
Number of pupils at first
= 1 u
= 24
Answer(s): 24