Opal bought 4 portable air-conditioners and 8 food processors. Each portable air-conditioner costs $476 more than each food processor. She spent 20% of her money on the food processors.

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

	Portable air-conditioners	Food processors	Total
Number	4	8
Value	1 u + $476	1 u
Total value	4 u + $1904	8 u
Comparing amounts spent on portable air-conditioners and food processors	80%	20%	100%

(a)
Amount that Opal spent on the portable air-conditioners
= 4(1 u + 476)
= 4 u + 1904 

Amount that Opal spent on the food processors
= 8 x 1 u
= 8 u

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

20% → 8 u

80% → 4 x 8 u = 32 u

32 u = 4 u + 1904
32 u - 4 u = 1904
28 u = 1904

1 u = 1904 ÷ 28 = 68

Cost of each portable air-conditioner 
= 68 + 476
= $544

(b)
100% → 8 u + 32 u = 40 u

Amount that Opal spent altogether
= 40 u
= 40 x 68
= $2720

Answer(s): (a) $544; (b) $2720