Class A, B and C 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 204. After Class B sold twice as many mini cupcakes as Class A and Class C sold ⁵₆ as many mini cupcakes as Class B, the average number of mini cupcakes the 3 classes had left was 50. How many mini cupcakes did Class A and Class C sell altogether?

Class A	Class B	Class C
1x3	2x3
	6x1	5x1
3 u	6 u	5 u

Class A : Class B : Class C
3 : 6 : 5

Total number of mini cupcakes that the 3 classes had at first
= 3 x 204
= 612

Number of mini cupcakes that the 3 classes left
= 3 x 50 
= 150

Number of mini cupcakes that were sold by 3 classes
= 612 - 150
= 462

3 u + 6 u + 5 u = 462
14 u = 462

1 u = 462 ÷ 14 = 33

Total number of mini cupcakes sold by Class A and Class C
= 3 u + 5 u
= 8 u
= 8 x 33
= 264

Answer(s): 264