Penelope bought 6 computers and 7 sandwich makers. Each computer costs $485 more than each sandwich maker. She spent 25% of her money on the sandwich makers.
- How much did each computer cost?
- How much did she spend altogether?
| |
Computers |
Sandwich makers |
Total |
| Number |
6 |
7 |
|
| Value |
1 u + $485 |
1 u |
|
| Total value |
6 u + $2910 |
7 u |
|
Comparing amounts
spent on computers
and sandwich makers |
75%
|
25% |
100% |
(a)
Amount that Penelope spent on the computers
= 6(1 u + 485)
= 6 u + 2910
Amount that Penelope spent on the sandwich makers
= 7 x 1 u
= 7 u
Amount that Penelope spent on the computers in percent
= 100% - 25%
= 75%
25% → 7 u
75% → 3 x 7 u = 21 u
21 u = 6 u + 2910
21 u - 6 u = 2910
15 u = 2910
1 u = 2910 ÷ 15 = 194
Cost of each computer
= 194 + 485
= $679
(b)
100% → 7 u + 21 u = 28 u
Amount that Penelope spent altogether
= 28 u
= 28 x 194
= $5432
Answer(s): (a) $679; (b) $5432
