Class T, U and V were given some sweets to sell for their charity drive. The average number of sweets the 3 classes had at first was 245. After Class U sold four times as many sweets as Class T and Class V sold ⁷₈ as many sweets as Class U, the average number of sweets the 3 classes had left was 41. How many sweets did Class T and Class V sell altogether?

Class T	Class U	Class V
1x2	4x2
	8x1	7x1
2 u	8 u	7 u

Class T : Class U : Class V
2 : 8 : 7

Total number of sweets that the 3 classes had at first
= 3 x 245
= 735

Number of sweets that the 3 classes left
= 3 x 41 
= 123

Number of sweets that were sold by 3 classes
= 735 - 123
= 612

2 u + 8 u + 7 u = 612
17 u = 612

1 u = 612 ÷ 17 = 36

Total number of sweets sold by Class T and Class V
= 2 u + 7 u
= 9 u
= 9 x 36
= 324

Answer(s): 324