Pamela bought 3 washing machines and 5 lamps. Each washing machine costs $256 more than each lamp. She spent 25% of her money on the lamps.
- How much did each washing machine cost?
- How much did she spend altogether?
| |
Washing machines |
Lamps |
Total |
| Number |
3 |
5 |
|
| Value |
1 u + $256 |
1 u |
|
| Total value |
3 u + $768 |
5 u |
|
Comparing amounts
spent on washing machines
and lamps |
75%
|
25% |
100% |
(a)
Amount that Pamela spent on the washing machines
= 3(1 u + 256)
= 3 u + 768
Amount that Pamela spent on the lamps
= 5 x 1 u
= 5 u
Amount that Pamela spent on the washing machines in percent
= 100% - 25%
= 75%
25% → 5 u
75% → 3 x 5 u = 15 u
15 u = 3 u + 768
15 u - 3 u = 768
12 u = 768
1 u = 768 ÷ 12 = 64
Cost of each washing machine
= 64 + 256
= $320
(b)
100% → 5 u + 15 u = 20 u
Amount that Pamela spent altogether
= 20 u
= 20 x 64
= $1280
Answer(s): (a) $320; (b) $1280
