Diana bought 4 washing machines and 5 speakers. Each washing machine costs $500 more than each speaker. She spent 20% of her money on the speakers.
- How much did each washing machine cost?
- How much did she spend altogether?
| |
Washing machines |
Speakers |
Total |
| Number |
4 |
5 |
|
| Value |
1 u + $500 |
1 u |
|
| Total value |
4 u + $2000 |
5 u |
|
Comparing amounts
spent on washing machines
and speakers |
80%
|
20% |
100% |
(a)
Amount that Diana spent on the washing machines
= 4(1 u + 500)
= 4 u + 2000
Amount that Diana spent on the speakers
= 5 x 1 u
= 5 u
Amount that Diana spent on the washing machines in percent
= 100% - 20%
= 80%
20% → 5 u
80% → 4 x 5 u = 20 u
20 u = 4 u + 2000
20 u - 4 u = 2000
16 u = 2000
1 u = 2000 ÷ 16 = 125
Cost of each washing machine
= 125 + 500
= $625
(b)
100% → 5 u + 20 u = 25 u
Amount that Diana spent altogether
= 25 u
= 25 x 125
= $3125
Answer(s): (a) $625; (b) $3125
