Gillian bought some gifts for her students at an average price of $13.90. If Gillian decided to buy a pen which cost $14 for her father and a bag which cost $33 for her mother, the average price of the gifts would become $15.10. How many gifts did Gillian buy for her students?
| |
Students |
Students and parents |
| Number |
1 u |
1 u + 2 |
| Value |
13.90 |
15.10 |
| Total Value |
13.90 u |
15.10 u + 30.20 |
Number of gifts that Gillian bought for her students = 1 u
Amount that Gillian spent on the gifts for her students
= 1 u x 13.90
= 13.90 u
Amount that $(Lizy) spent if she bought for her parents
= 14 + 33
= $47
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
= 15.10(1 u + 2)
= 15.10 u + 30.20
13.9 u + 47 = 15.10 u + 30.20
15.10 u - 13.9 u = 47 - 30.20
1.2 u = 16.80
1 u = 16.80 ÷ 1.2 = 14
Number of gifts that she bought for her students
= 1 u
= 14
Answer(s): 14
