Gwen bought some gifts for her students at an average price of $12.30. If Gwen decided to buy a pen which cost $17 for her father and a bag which cost $43 for her mother, the average price of the gifts would become $18.20. How many gifts did Gwen buy for her students?
| |
Students |
Students and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.30 |
18.20 |
| Total Value |
12.30 u |
18.20 u + 36.40 |
Number of gifts that Gwen bought for her students = 1 u
Amount that Gwen spent on the gifts for her students
= 1 u x 12.30
= 12.30 u
Amount that $(Lizy) spent if she bought for her parents
= 17 + 43
= $60
Total number of items bought if she bought for her parents and her students
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her students
= 18.20(1 u + 2)
= 18.20 u + 36.40
12.3 u + 60 = 18.20 u + 36.40
18.20 u - 12.3 u = 60 - 36.40
5.9 u = 23.60
1 u = 23.60 ÷ 5.9 = 4
Number of gifts that she bought for her students
= 1 u
= 4
Answer(s): 4
