Class T, U and V were given some mochi balls to sell for their charity drive. The average number of mochi balls the 3 classes had at first was 248. After Class U sold twice as many mochi balls as Class T and Class V sold ⁵₆ as many mochi balls as Class U, the average number of mochi balls the 3 classes had left was 52. How many mochi balls did Class T and Class V sell altogether?

Class T	Class U	Class V
1x3	2x3
	6x1	5x1
3 u	6 u	5 u

Class T : Class U : Class V
3 : 6 : 5

Total number of mochi balls that the 3 classes had at first
= 3 x 248
= 744

Number of mochi balls that the 3 classes left
= 3 x 52 
= 156

Number of mochi balls that were sold by 3 classes
= 744 - 156
= 588

3 u + 6 u + 5 u = 588
14 u = 588

1 u = 588 ÷ 14 = 42

Total number of mochi balls sold by Class T and Class V
= 3 u + 5 u
= 8 u
= 8 x 42
= 336

Answer(s): 336