Class A, B and C were given some mini cupcakes to sell for their charity drive. The average number of mini cupcakes the 3 classes had at first was 235. After Class B sold four times 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 60. How many mini cupcakes did Class A and Class C sell altogether?

Class A	Class B	Class C
1x3	4x3
	6x2	5x2
3 u	12 u	10 u

Class A : Class B : Class C
3 : 12 : 10

Total number of mini cupcakes that the 3 classes had at first
= 3 x 235
= 705

Number of mini cupcakes that the 3 classes left
= 3 x 60 
= 180

Number of mini cupcakes that were sold by 3 classes
= 705 - 180
= 525

3 u + 12 u + 10 u = 525
25 u = 525

1 u = 525 ÷ 25 = 21

Total number of mini cupcakes sold by Class A and Class C
= 3 u + 10 u
= 13 u
= 13 x 21
= 273

Answer(s): 273