Penelope bought 6 notebooks and 9 lamps. Each notebook costs $301 more than each lamp. She spent 25% of her money on the lamps.
- How much did each notebook cost?
- How much did she spend altogether?
| |
Notebooks |
Lamps |
Total |
| Number |
6 |
9 |
|
| Value |
1 u + $301 |
1 u |
|
| Total value |
6 u + $1806 |
9 u |
|
Comparing amounts
spent on notebooks
and lamps |
75%
|
25% |
100% |
(a)
Amount that Penelope spent on the notebooks
= 6(1 u + 301)
= 6 u + 1806
Amount that Penelope spent on the lamps
= 9 x 1 u
= 9 u
Amount that Penelope spent on the notebooks in percent
= 100% - 25%
= 75%
25% → 9 u
75% → 3 x 9 u = 27 u
27 u = 6 u + 1806
27 u - 6 u = 1806
21 u = 1806
1 u = 1806 ÷ 21 = 86
Cost of each notebook
= 86 + 301
= $387
(b)
100% → 9 u + 27 u = 36 u
Amount that Penelope spent altogether
= 36 u
= 36 x 86
= $3096
Answer(s): (a) $387; (b) $3096
