Opal bought some gifts for her colleagues at an average price of $11.50. If Opal decided to buy a pen which cost $14 for her father and a bag which cost $45 for her mother, the average price of the gifts would become $15.10. How many gifts did Opal buy for her colleagues?
| |
Colleagues |
Colleagues and parents |
| Number |
1 u |
1 u + 2 |
| Value |
11.50 |
15.10 |
| Total Value |
11.50 u |
15.10 u + 30.20 |
Number of gifts that Opal bought for her colleagues = 1 u
Amount that Opal spent on the gifts for her colleagues
= 1 u x 11.50
= 11.50 u
Amount that $(Lizy) spent if she bought for her parents
= 14 + 45
= $59
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
= 15.10(1 u + 2)
= 15.10 u + 30.20
11.5 u + 59 = 15.10 u + 30.20
15.10 u - 11.5 u = 59 - 30.20
3.6 u = 28.80
1 u = 28.80 ÷ 3.6 = 8
Number of gifts that she bought for her colleagues
= 1 u
= 8
Answer(s): 8
