Class U, V and W were given some mini cupcakes to sell for their fund-raising project. The average number of mini cupcakes the 3 classes had at first was 241. After Class V sold four times as many mini cupcakes as Class U and Class W sold ⁷₈ as many mini cupcakes as Class V, the average number of mini cupcakes the 3 classes had left was 54. How many mini cupcakes did Class U and Class W sell altogether?

Class U	Class V	Class W
1x2	4x2
	8x1	7x1
2 u	8 u	7 u

Class U : Class V : Class W
2 : 8 : 7

Total number of mini cupcakes that the 3 classes had at first
= 3 x 241
= 723

Number of mini cupcakes that the 3 classes left
= 3 x 54 
= 162

Number of mini cupcakes that were sold by 3 classes
= 723 - 162
= 561

2 u + 8 u + 7 u = 561
17 u = 561

1 u = 561 ÷ 17 = 33

Total number of mini cupcakes sold by Class U and Class W
= 2 u + 7 u
= 9 u
= 9 x 33
= 297

Answer(s): 297