The ratio of the number of tarts in Container S to the number of tarts in Container T was 9 : 5. 20% of the tarts in Container S and 0.6 of those in Container T were mango. After transferring the tarts between the 2 containers, the number of chocolate tarts in both containers are the same. Likewise, the number of mango tarts in both containers are the same. If a total of 240 tarts were moved, how many more tarts were there in Container S than Container T at first?

Container S		Container T
9 u		5 u
Mango	Chocolate	Mango	Chocolate
1.8 u	7.2 u	3 u	2 u
+ 0.6 u	- 2.6 u	- 0.6 u	+ 2.6 u
2.4 u	4.6 u	2.4 u	4.6 u

Number of mango tarts in Container S
= 20% x 9 u
= ²⁰₁₀₀ x 9 u
= 1.8 u

Number of chocolate tarts in Container S
= 9 u - 1.8 u
= 7.2 u

Number of mango tarts in Container T
= 0.6 x 5 u
= 3 u

Number of chocolate tarts in Container T
= 5 u - 3 u
= 2 u

Number of mango tarts in each container in the end
= (1.8 u + 3 u) ÷ 2
= 4.8 u ÷ 2
= 2.4 u

Number of chocolate tarts in each container in the end
= (7.2 u + 2 u) ÷ 2
= 9.2 u ÷ 2
= 4.6 u

Number of tarts moved
= 0.6 u + 2.6 u
= 3.2 u

3.2 u = 240

1 u = 240 ÷ 3.2 = 75

Number of more tarts in Container S than Container T at first
= 9 u - 5 u
= 4 u
= 4 x 75
= 300

Answer(s): 300