Zara bought some presents for her students at an average price of $11.50. If Zara decided to buy a pen which cost $12 for her father and a bag which cost $48 for her mother, the average price of the presents would become $15.20. How many presents did Zara buy for her students?
| |
Students |
Students and parents |
| Number |
1 u |
1 u + 2 |
| Value |
11.50 |
15.20 |
| Total Value |
11.50 u |
15.20 u + 30.40 |
Number of presents that Zara bought for her students = 1 u
Amount that Zara spent on the presents for her students
= 1 u x 11.50
= 11.50 u
Amount that $(Lizy) spent if she bought for her parents
= 12 + 48
= $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
= 15.20(1 u + 2)
= 15.20 u + 30.40
11.5 u + 60 = 15.20 u + 30.40
15.20 u - 11.5 u = 60 - 30.40
3.7 u = 29.60
1 u = 29.60 ÷ 3.7 = 8
Number of presents that she bought for her students
= 1 u
= 8
Answer(s): 8
