Class E, F and G were given some sweets to sell for their charity drive. The average number of sweets the 3 classes had at first was 240. After Class F sold thrice as many sweets as Class E and Class G sold ⁵₆ as many sweets as Class F, the average number of sweets the 3 classes had left was 58. How many sweets did Class E and Class G sell altogether?

Class E	Class F	Class G
1x2	3x2
	6x1	5x1
2 u	6 u	5 u

Class E : Class F : Class G
2 : 6 : 5

Total number of sweets that the 3 classes had at first
= 3 x 240
= 720

Number of sweets that the 3 classes left
= 3 x 58 
= 174

Number of sweets that were sold by 3 classes
= 720 - 174
= 546

2 u + 6 u + 5 u = 546
13 u = 546

1 u = 546 ÷ 13 = 42

Total number of sweets sold by Class E and Class G
= 2 u + 5 u
= 7 u
= 7 x 42
= 294

Answer(s): 294