The total cost of the laptop, the lamp and the water heater is $1200. The water heater costs twice as much as the lamp. The laptop costs thrice as much as the total price of the water heater and lamp. How much more does the water heater cost than the laptop?
| Water Heater |
Lamp |
Laptop |
| 2 u |
1 u |
|
| 3 u |
9 u |
| 2 u |
1 u |
9 u |
Cost of the lamp = 1 u
Cost of the water heater = 2 u
Total cost of the lamp and the water heater
= 1 u + 2 u
= 3 u
Cost of the laptop
= 3 x 3 u
= 9 u
Total cost of the water heater, the lamp and laptop
= 9 u + 1 u + 2 u
= 12 u
12 u = 1200
1 u = 1200 ÷ 12 = 100
Amount that the laptop cost more than the water heater
= 9 u - 2 u
= 7 u
= 7 x 100
= $700
Answer(s): $700
