Class H, J and K 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 217. After Class J sold twice as many mini cupcakes as Class H and Class K sold ³₄ as many mini cupcakes as Class J, the average number of mini cupcakes the 3 classes had left was 52. How many mini cupcakes did Class H and Class K sell altogether?

Class H	Class J	Class K
1x2	2x2
	4x1	3x1
2 u	4 u	3 u

Class H : Class J : Class K
2 : 4 : 3

Total number of mini cupcakes that the 3 classes had at first
= 3 x 217
= 651

Number of mini cupcakes that the 3 classes left
= 3 x 52 
= 156

Number of mini cupcakes that were sold by 3 classes
= 651 - 156
= 495

2 u + 4 u + 3 u = 495
9 u = 495

1 u = 495 ÷ 9 = 55

Total number of mini cupcakes sold by Class H and Class K
= 2 u + 3 u
= 5 u
= 5 x 55
= 275

Answer(s): 275