Nicole bought 3 portable air-conditioners and 7 sandwich makers. Each portable air-conditioner costs $475 more than each sandwich maker. She spent 20% of her money on the sandwich makers.

1. How much did each portable air-conditioner cost? 
2. How much did she spend altogether?

	Portable air-conditioners	Sandwich makers	Total
Number	3	7
Value	1 u + $475	1 u
Total value	3 u + $1425	7 u
Comparing amounts spent on portable air-conditioners and sandwich makers	80%	20%	100%

(a)
Amount that Nicole spent on the portable air-conditioners
= 3(1 u + 475)
= 3 u + 1425 

Amount that Nicole spent on the sandwich makers
= 7 x 1 u
= 7 u

Amount that Nicole spent on the portable air-conditioners in percent
= 100% - 20%
= 80%

20% → 7 u

80% → 4 x 7 u = 28 u

28 u = 3 u + 1425
28 u - 3 u = 1425
25 u = 1425

1 u = 1425 ÷ 25 = 57

Cost of each portable air-conditioner 
= 57 + 475
= $532

(b)
100% → 7 u + 28 u = 35 u

Amount that Nicole spent altogether
= 35 u
= 35 x 57
= $1995

Answer(s): (a) $532; (b) $1995