Shannon bought some presents for her colleagues at an average price of $10.70. If Shannon decided to buy a pen which cost $15 for her father and a bag which cost $48 for her mother, the average price of the presents would become $15.90. How many presents did Shannon buy for her colleagues?
| |
Colleagues |
Colleagues and parents |
| Number |
1 u |
1 u + 2 |
| Value |
10.70 |
15.90 |
| Total Value |
10.70 u |
15.90 u + 31.80 |
Number of presents that Shannon bought for her colleagues = 1 u
Amount that Shannon spent on the presents for her colleagues
= 1 u x 10.70
= 10.70 u
Amount that $(Lizy) spent if she bought for her parents
= 15 + 48
= $63
Total number of items bought if she bought for her parents and her colleagues
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her colleagues
= 15.90(1 u + 2)
= 15.90 u + 31.80
10.7 u + 63 = 15.90 u + 31.80
15.90 u - 10.7 u = 63 - 31.80
5.2 u = 31.20
1 u = 31.20 ÷ 5.2 = 6
Number of presents that she bought for her colleagues
= 1 u
= 6
Answer(s): 6
