Class C, D and E were given some mini cupcakes to sell for their charity drive. The average number of mini cupcakes the 3 classes had at first was 219. After Class D sold twice as many mini cupcakes as Class C and Class E sold ³₄ as many mini cupcakes as Class D, the average number of mini cupcakes the 3 classes had left was 51. How many mini cupcakes did Class C and Class E sell altogether?

Class C	Class D	Class E
1x2	2x2
	4x1	3x1
2 u	4 u	3 u

Class C : Class D : Class E
2 : 4 : 3

Total number of mini cupcakes that the 3 classes had at first
= 3 x 219
= 657

Number of mini cupcakes that the 3 classes left
= 3 x 51 
= 153

Number of mini cupcakes that were sold by 3 classes
= 657 - 153
= 504

2 u + 4 u + 3 u = 504
9 u = 504

1 u = 504 ÷ 9 = 56

Total number of mini cupcakes sold by Class C and Class E
= 2 u + 3 u
= 5 u
= 5 x 56
= 280

Answer(s): 280