Hilda bought some presents for her colleagues at an average price of $12.60. If Hilda decided to buy a pen which cost $16 for her father and a bag which cost $32 for her mother, the average price of the presents would become $16.40. How many presents did Hilda buy for her colleagues?
| |
Colleagues |
Colleagues and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.60 |
16.40 |
| Total Value |
12.60 u |
16.40 u + 32.80 |
Number of presents that Hilda bought for her colleagues = 1 u
Amount that Hilda spent on the presents for her colleagues
= 1 u x 12.60
= 12.60 u
Amount that $(Lizy) spent if she bought for her parents
= 16 + 32
= $48
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
= 16.40(1 u + 2)
= 16.40 u + 32.80
12.6 u + 48 = 16.40 u + 32.80
16.40 u - 12.6 u = 48 - 32.80
3.8 u = 15.20
1 u = 15.20 ÷ 3.8 = 4
Number of presents that she bought for her colleagues
= 1 u
= 4
Answer(s): 4
