The ratio of the number of tarts in Container W to the number of tarts in Container X was 5 : 3. 10% of the tarts in Container W and 0.8 of those in Container X were mango. After transferring the tarts between the 2 containers, the number of strawberry tarts in both containers are the same. Likewise, the number of mango tarts in both containers are the same. If a total of 290 tarts were moved, how many more tarts were there in Container W than Container X at first?

Container W		Container X
5 u		3 u
Mango	Strawberry	Mango	Strawberry
0.5 u	4.5 u	2.4 u	0.6 u
+ 0.95 u	- 1.95 u	- 0.95 u	+ 1.95 u
1.45 u	2.55 u	1.45 u	2.55 u

Number of mango tarts in Container W
= 10% x 5 u
= ¹⁰₁₀₀ x 5 u
= 0.5 u

Number of strawberry tarts in Container W
= 5 u - 0.5 u
= 4.5 u

Number of mango tarts in Container X
= 0.8 x 3 u
= 2.4 u

Number of strawberry tarts in Container X
= 3 u - 2.4 u
= 0.6 u

Number of mango tarts in each container in the end
= (0.5 u + 2.4 u) ÷ 2
= 2.9 u ÷ 2
= 1.45 u

Number of strawberry tarts in each container in the end
= (4.5 u + 0.6 u) ÷ 2
= 5.1 u ÷ 2
= 2.55 u

Number of tarts moved
= 0.95 u + 1.95 u
= 2.9 u

2.9 u = 290

1 u = 290 ÷ 2.9 = 100

Number of more tarts in Container W than Container X at first
= 5 u - 3 u
= 2 u
= 2 x 100
= 200

Answer(s): 200