Class G, H and J were given some chocolate bars to sell for their donation drive. The average number of chocolate bars the 3 classes had at first was 222. After Class H sold twice as many chocolate bars as Class G and Class J sold ²₃ as many chocolate bars as Class H, the average number of chocolate bars the 3 classes had left was 53. How many chocolate bars did Class G and Class J sell altogether?

Class G	Class H	Class J
1x3	2x3
	3x2	2x2
3 u	6 u	4 u

Class G : Class H : Class J
3 : 6 : 4

Total number of chocolate bars that the 3 classes had at first
= 3 x 222
= 666

Number of chocolate bars that the 3 classes left
= 3 x 53 
= 159

Number of chocolate bars that were sold by 3 classes
= 666 - 159
= 507

3 u + 6 u + 4 u = 507
13 u = 507

1 u = 507 ÷ 13 = 39

Total number of chocolate bars sold by Class G and Class J
= 3 u + 4 u
= 7 u
= 7 x 39
= 273

Answer(s): 273