Zoe bought some presents for her relatives at an average price of $12.70. If Zoe decided to buy a pen which cost $17 for her father and a bag which cost $42 for her mother, the average price of the presents would become $14.80. How many presents did Zoe buy for her relatives?
| |
Relatives |
Relatives and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.70 |
14.80 |
| Total Value |
12.70 u |
14.80 u + 29.60 |
Number of presents that Zoe bought for her relatives = 1 u
Amount that Zoe spent on the presents for her relatives
= 1 u x 12.70
= 12.70 u
Amount that $(Lizy) spent if she bought for her parents
= 17 + 42
= $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
= 14.80(1 u + 2)
= 14.80 u + 29.60
12.7 u + 59 = 14.80 u + 29.60
14.80 u - 12.7 u = 59 - 29.60
2.1 u = 29.40
1 u = 29.40 ÷ 2.1 = 14
Number of presents that she bought for her relatives
= 1 u
= 14
Answer(s): 14
