Xandra bought some presents for her students at an average price of $13.80. If Xandra decided to buy a pen which cost $19 for her father and a bag which cost $41 for her mother, the average price of the presents would become $17.40. How many presents did Xandra buy for her students?
| |
Students |
Students and parents |
| Number |
1 u |
1 u + 2 |
| Value |
13.80 |
17.40 |
| Total Value |
13.80 u |
17.40 u + 34.80 |
Number of presents that Xandra bought for her students = 1 u
Amount that Xandra spent on the presents for her students
= 1 u x 13.80
= 13.80 u
Amount that $(Lizy) spent if she bought for her parents
= 19 + 41
= $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
= 17.40(1 u + 2)
= 17.40 u + 34.80
13.8 u + 60 = 17.40 u + 34.80
17.40 u - 13.8 u = 60 - 34.80
3.6 u = 25.20
1 u = 25.20 ÷ 3.6 = 7
Number of presents that she bought for her students
= 1 u
= 7
Answer(s): 7
