Class G, H and J were given some sweets to sell for their charity drive. The average number of sweets the 3 classes had at first was 238. After Class H sold twice as many sweets as Class G and Class J sold ⁷₈ as many sweets as Class H, the average number of sweets the 3 classes had left was 48. How many sweets did Class G and Class J sell altogether?

Class G	Class H	Class J
1x4	2x4
	8x1	7x1
4 u	8 u	7 u

Class G : Class H : Class J
4 : 8 : 7

Total number of sweets that the 3 classes had at first
= 3 x 238
= 714

Number of sweets that the 3 classes left
= 3 x 48 
= 144

Number of sweets that were sold by 3 classes
= 714 - 144
= 570

4 u + 8 u + 7 u = 570
19 u = 570

1 u = 570 ÷ 19 = 30

Total number of sweets sold by Class G and Class J
= 4 u + 7 u
= 11 u
= 11 x 30
= 330

Answer(s): 330