Vaidev had three boxes, containing a total of 720 paper bowls. The number of paper bowls in Box R to the total number of paper bowls was 3 : 8. He sold 331 paper bowls from Box S and sold ¹₃ of the paper bowls in Box T. The number of paper bowls left in Box S to the number of paper bowls left in Box T was 2 : 1. How many paper bowls were there in Box S at first?

	Box R	Box S	Box T	Total
Before	3 u	5 u (450)		8 u (720)
		4 p + 331	3 p
Change		- 331	- 1 p
			2 p
After		2x2 = 4 p	1x2 = 2 p

8 u = 720
1 u = 720 ÷ 8 = 90

Number of paper bowls in Box S and Box T at first
= 5 u
= 5 x 90
= 450

The number of bowls left in T is the repeated identity.
LCM of 1 and 2 = 2

4 p + 331 + 3 p = 450
4 p + 3 p = 450 - 331
7 p = 119

1 p = 119 ÷ 7 = 17

Number of bowls in Box S at first
= 4 p + 331
= 4 x 17 + 331
= 68 + 331
= 399

Answer(s):399