The average amount of money collected by a group of students at a flag day event was $119. When another 12 students turned up to help, the total amount donated increased by $714 and the average amount of money collected became $85. How many students were there in the group at first?
|
Number of students at first |
Number of students in the end |
Number |
1 u |
1 u + 12 |
Value |
119 |
85 |
Total Value |
119 u + 714 |
85 u + 1020 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 119
= 119 u
Total amount collected by the students in the end
= 85 x (1 u + 12)
= 85 u + 1020
119 u + 714 = 85 u + 1020
119 u - 85 u = 1020 - 714
34 u = 306
1 u = 306 ÷ 34 = 9
Number of students at first
= 1 u
= 9
Answer(s): 9