Class L, M and N were given some candy canes to sell for their donation drive. The average number of candy canes the 3 classes had at first was 243. After Class M sold four times as many candy canes as Class L and Class N sold ⁷₈ as many candy canes as Class M, the average number of candy canes the 3 classes had left was 56. How many candy canes did Class L and Class N sell altogether?

Class L	Class M	Class N
1x2	4x2
	8x1	7x1
2 u	8 u	7 u

Class L : Class M : Class N
2 : 8 : 7

Total number of candy canes that the 3 classes had at first
= 3 x 243
= 729

Number of candy canes that the 3 classes left
= 3 x 56 
= 168

Number of candy canes that were sold by 3 classes
= 729 - 168
= 561

2 u + 8 u + 7 u = 561
17 u = 561

1 u = 561 ÷ 17 = 33

Total number of candy canes sold by Class L and Class N
= 2 u + 7 u
= 9 u
= 9 x 33
= 297

Answer(s): 297