The total cost of the washing machine, the kettle and the speaker is $300. The speaker costs four times as much as the kettle. The washing machine costs twice as much as the total price of the speaker and kettle. How much less does the speaker cost than the washing machine?
| Speaker |
Kettle |
Washing Machine |
| 4 u |
1 u |
|
| 5 u |
10 u |
| 4 u |
1 u |
10 u |
Cost of the kettle = 1 u
Cost of the speaker = 4 u
Total cost of the kettle and the speaker
= 1 u + 4 u
= 5 u
Cost of the washing machine
= 2 x 5 u
= 10 u
Total cost of the speaker, the kettle and washing machine
= 10 u + 1 u + 4 u
= 15 u
15 u = 300
1 u = 300 ÷ 15 = 20
Amount that the speaker cost less than the washing machine
= 10 u - 4 u
= 6 u
= 6 x 20
= $120
Answer(s): $120
