Dana bought 2 laptops and 7 speakers. Each laptop costs $468 more than each speaker. She spent 20% of her money on the speakers.
- How much did each laptop cost?
- How much did she spend altogether?
| |
Laptops |
Speakers |
Total |
| Number |
2 |
7 |
|
| Value |
1 u + $468 |
1 u |
|
| Total value |
2 u + $936 |
7 u |
|
Comparing amounts
spent on laptops
and speakers |
80%
|
20% |
100% |
(a)
Amount that Dana spent on the laptops
= 2(1 u + 468)
= 2 u + 936
Amount that Dana spent on the speakers
= 7 x 1 u
= 7 u
Amount that Dana spent on the laptops in percent
= 100% - 20%
= 80%
20% → 7 u
80% → 4 x 7 u = 28 u
28 u = 2 u + 936
28 u - 2 u = 936
26 u = 936
1 u = 936 ÷ 26 = 36
Cost of each laptop
= 36 + 468
= $504
(b)
100% → 7 u + 28 u = 35 u
Amount that Dana spent altogether
= 35 u
= 35 x 36
= $1260
Answer(s): (a) $504; (b) $1260
