Usha bought 2 televisions and 10 lamps. Each television costs $280 more than each lamp. She spent 25% of her money on the lamps.
- How much did each television cost?
- How much did she spend altogether?
| |
Televisions |
Lamps |
Total |
| Number |
2 |
10 |
|
| Value |
1 u + $280 |
1 u |
|
| Total value |
2 u + $560 |
10 u |
|
Comparing amounts
spent on televisions
and lamps |
75%
|
25% |
100% |
(a)
Amount that Usha spent on the televisions
= 2(1 u + 280)
= 2 u + 560
Amount that Usha spent on the lamps
= 10 x 1 u
= 10 u
Amount that Usha spent on the televisions in percent
= 100% - 25%
= 75%
25% → 10 u
75% → 3 x 10 u = 30 u
30 u = 2 u + 560
30 u - 2 u = 560
28 u = 560
1 u = 560 ÷ 28 = 20
Cost of each television
= 20 + 280
= $300
(b)
100% → 10 u + 30 u = 40 u
Amount that Usha spent altogether
= 40 u
= 40 x 20
= $800
Answer(s): (a) $300; (b) $800
