Hazel bought 3 computers and 10 sandwich makers. Each computer costs $290 more than each sandwich maker. She spent 10% of her money on the sandwich makers.
- How much did each computer cost?
- How much did she spend altogether?
| |
Computers |
Sandwich makers |
Total |
| Number |
3 |
10 |
|
| Value |
1 u + $290 |
1 u |
|
| Total value |
3 u + $870 |
10 u |
|
Comparing amounts
spent on computers
and sandwich makers |
90%
|
10% |
100% |
(a)
Amount that Hazel spent on the computers
= 3(1 u + 290)
= 3 u + 870
Amount that Hazel spent on the sandwich makers
= 10 x 1 u
= 10 u
Amount that Hazel spent on the computers in percent
= 100% - 10%
= 90%
10% → 10 u
90% → 9 x 10 u = 90 u
90 u = 3 u + 870
90 u - 3 u = 870
87 u = 870
1 u = 870 ÷ 87 = 10
Cost of each computer
= 10 + 290
= $300
(b)
100% → 10 u + 90 u = 100 u
Amount that Hazel spent altogether
= 100 u
= 100 x 10
= $1000
Answer(s): (a) $300; (b) $1000
