The ratio of the number of tarts in Container D to the number of tarts in Container E was 5 : 3. 20% of the tarts in Container D and 0.8 of those in Container E were matcha. After transferring the tarts between the 2 containers, the number of peach tarts in both containers are the same. Likewise, the number of matcha tarts in both containers are the same. If a total of 240 tarts were moved, how many more tarts were there in Container D than Container E at first?

Container D		Container E
5 u		3 u
Matcha	Peach	Matcha	Peach
1 u	4 u	2.4 u	0.6 u
+ 0.7 u	- 1.7 u	- 0.7 u	+ 1.7 u
1.7 u	2.3 u	1.7 u	2.3 u

Number of matcha tarts in Container D
= 20% x 5 u
= ²⁰₁₀₀ x 5 u
= 1 u

Number of peach tarts in Container D
= 5 u - 1 u
= 4 u

Number of matcha tarts in Container E
= 0.8 x 3 u
= 2.4 u

Number of peach tarts in Container E
= 3 u - 2.4 u
= 0.6 u

Number of matcha tarts in each container in the end
= (1 u + 2.4 u) ÷ 2
= 3.4 u ÷ 2
= 1.7 u

Number of peach tarts in each container in the end
= (4 u + 0.6 u) ÷ 2
= 4.6 u ÷ 2
= 2.3 u

Number of tarts moved
= 0.7 u + 1.7 u
= 2.4 u

2.4 u = 240

1 u = 240 ÷ 2.4 = 100

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

Answer(s): 200