The average amount of money collected by a group of students at a flag day event was $101. When another 15 students turned up to help, the total amount donated increased by $501 and the average amount of money collected became $75. How many students were there in the group in the end?
|
Number of students at first |
Number of students in the end |
Number |
1 u |
1 u + 15 |
Value |
101 |
75 |
Total Value |
101 u + 501 |
75 u + 1125 |
Number of students at first = 1 u
Total amount collected by the students at first
= 1 u x 101
= 101 u
Total amount collected by the students in the end
= 75 x (1 u + 15)
= 75 u + 1125
101 u + 501 = 75 u + 1125
101 u - 75 u = 1125 - 501
26 u = 624
1 u = 624 ÷ 26 = 24
Number of students in the end
= 1 u + 15
= 24 + 15
= 39
Answer(s): 39