Opal bought 3 washing machines and 4 sandwich makers. Each washing machine costs $369 more than each sandwich maker. She spent 25% of her money on the sandwich makers.
- How much did each washing machine cost?
- How much did she spend altogether?
|
Washing machines |
Sandwich makers |
Total |
Number |
3 |
4 |
|
Value |
1 u + $369 |
1 u |
|
Total value |
3 u + $1107 |
4 u |
|
Comparing amounts spent on washing machines and sandwich makers |
75%
|
25% |
100% |
(a)
Amount that Opal spent on the washing machines
= 3(1 u + 369)
= 3 u + 1107
Amount that Opal spent on the sandwich makers
= 4 x 1 u
= 4 u
Amount that Opal spent on the washing machines in percent
= 100% - 25%
= 75%
25% → 4 u
75% → 3 x 4 u = 12 u
12 u = 3 u + 1107
12 u - 3 u = 1107
9 u = 1107
1 u = 1107 ÷ 9 = 123
Cost of each washing machine
= 123 + 369
= $492
(b)
100% → 4 u + 12 u = 16 u
Amount that Opal spent altogether
= 16 u
= 16 x 123
= $1968
Answer(s): (a) $492; (b) $1968