Irene bought some souvenirs for her colleagues at an average price of $13.40. If Irene decided to buy a pen which cost $15 for her father and a bag which cost $47 for her mother, the average price of the souvenirs would become $17.80. How many souvenirs did Irene buy for her colleagues?
| |
Colleagues |
Colleagues and parents |
| Number |
1 u |
1 u + 2 |
| Value |
13.40 |
17.80 |
| Total Value |
13.40 u |
17.80 u + 35.60 |
Number of souvenirs that Irene bought for her colleagues = 1 u
Amount that Irene spent on the souvenirs for her colleagues
= 1 u x 13.40
= 13.40 u
Amount that $(Lizy) spent if she bought for her parents
= 15 + 47
= $62
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
= 17.80(1 u + 2)
= 17.80 u + 35.60
13.4 u + 62 = 17.80 u + 35.60
17.80 u - 13.4 u = 62 - 35.60
4.4 u = 26.40
1 u = 26.40 ÷ 4.4 = 6
Number of souvenirs that she bought for her colleagues
= 1 u
= 6
Answer(s): 6
