Class F, G and H were given some chocolate bars to sell for their donation drive. The average number of chocolate bars the 3 classes had at first was 230. After Class G sold thrice as many chocolate bars as Class F and Class H sold ⁶₇ as many chocolate bars as Class G, the average number of chocolate bars the 3 classes had left was 46. How many chocolate bars did Class F and Class H sell altogether?

Class F	Class G	Class H
1x7	3x7
	7x3	6x3
7 u	21 u	18 u

Class F : Class G : Class H
7 : 21 : 18

Total number of chocolate bars that the 3 classes had at first
= 3 x 230
= 690

Number of chocolate bars that the 3 classes left
= 3 x 46 
= 138

Number of chocolate bars that were sold by 3 classes
= 690 - 138
= 552

7 u + 21 u + 18 u = 552
46 u = 552

1 u = 552 ÷ 46 = 12

Total number of chocolate bars sold by Class F and Class H
= 7 u + 18 u
= 25 u
= 25 x 12
= 300

Answer(s): 300