Betty bought 2 televisions and 3 lamps. Each television costs $385 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 |
3 |
|
| Value |
1 u + $385 |
1 u |
|
| Total value |
2 u + $770 |
3 u |
|
Comparing amounts
spent on televisions
and lamps |
75%
|
25% |
100% |
(a)
Amount that Betty spent on the televisions
= 2(1 u + 385)
= 2 u + 770
Amount that Betty spent on the lamps
= 3 x 1 u
= 3 u
Amount that Betty spent on the televisions in percent
= 100% - 25%
= 75%
25% → 3 u
75% → 3 x 3 u = 9 u
9 u = 2 u + 770
9 u - 2 u = 770
7 u = 770
1 u = 770 ÷ 7 = 110
Cost of each television
= 110 + 385
= $495
(b)
100% → 3 u + 9 u = 12 u
Amount that Betty spent altogether
= 12 u
= 12 x 110
= $1320
Answer(s): (a) $495; (b) $1320
