Jeremy buys a blouse, a jumpsuit and a dress. The average cost of these items is $78. The cost of the dress is four times the total cost of the blouse and the jumpsuit. If the blouse costs $14, find the difference in cost between the jumpsuit and the dress.
Total cost of the 3 items
= 3 x 78
= $234

Total cost of the blouse and the jumpsuit = 1 u
Cost of the dress = 4 u

Total cost of the 3 items 
= 1 u + 4 u
= 5 u

5 u = 234 

1 u = 234 ÷ 5 = 46.80

Total cost of the blouse and the jumpsuit = $46.80

Cost of the jumpsuit 
= 46.80 - 14
= $32.80

Cost of the dress
= 4 u
= 4 x 46.80
= $187.20

Difference in cost between the jumpsuit and the dress
= 187.20 - 32.80
= $154.40

Answer(s): $154.40