Dylan had three boxes, containing a total of 1100 plastic plates. The number of plastic plates in Box V to the total number of plastic plates was 3 : 11. He sold 350 plastic plates from Box W and sold ¹₃ of the plastic plates in Box X. The number of plastic plates left in Box W to the number of plastic plates left in Box X was 3 : 1. How many plastic plates were there in Box W at first?

	Box V	Box W	Box X	Total
Before	3 u	8 u (800)		11 u (1100)
		6 p + 350	3 p
Change		- 350	- 1 p
			2 p
After		3x2 = 6 p	1x2 = 2 p

11 u = 1100
1 u = 1100 ÷ 11 = 100

Number of plastic plates in Box W and Box X at first
= 8 u
= 8 x 100
= 800

The number of plates left in X is the repeated identity.
LCM of 1 and 2 = 2

6 p + 350 + 3 p = 800
6 p + 3 p = 800 - 350
9 p = 450

1 p = 450 ÷ 9 = 50

Number of plates in Box W at first
= 6 p + 350
= 6 x 50 + 350
= 300 + 350
= 650

Answer(s):650