Min bought some presents for her relatives at an average price of $11.20. If Min decided to buy a pen which cost $19 for her father and a bag which cost $40 for her mother, the average price of the presents would become $17.30. How many presents did Min buy for her relatives?
| |
Relatives |
Relatives and parents |
| Number |
1 u |
1 u + 2 |
| Value |
11.20 |
17.30 |
| Total Value |
11.20 u |
17.30 u + 34.60 |
Number of presents that Min bought for her relatives = 1 u
Amount that Min spent on the presents for her relatives
= 1 u x 11.20
= 11.20 u
Amount that $(Lizy) spent if she bought for her parents
= 19 + 40
= $59
Total number of items bought if she bought for her parents and her relatives
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her relatives
= 17.30(1 u + 2)
= 17.30 u + 34.60
11.2 u + 59 = 17.30 u + 34.60
17.30 u - 11.2 u = 59 - 34.60
6.1 u = 24.40
1 u = 24.40 ÷ 6.1 = 4
Number of presents that she bought for her relatives
= 1 u
= 4
Answer(s): 4
