The ratio of the number of tarts in Container R to the number of tarts in Container S was 9 : 5. 20% of the tarts in Container R and 0.6 of those in Container S were strawberry. After transferring the tarts between the 2 containers, the number of mocha tarts in both containers are the same. Likewise, the number of strawberry tarts in both containers are the same. If a total of 192 tarts were moved, how many more tarts were there in Container R than Container S at first?

Container R		Container S
9 u		5 u
Strawberry	Mocha	Strawberry	Mocha
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 strawberry tarts in Container R
= 20% x 9 u
= ²⁰₁₀₀ x 9 u
= 1.8 u

Number of mocha tarts in Container R
= 9 u - 1.8 u
= 7.2 u

Number of strawberry tarts in Container S
= 0.6 x 5 u
= 3 u

Number of mocha tarts in Container S
= 5 u - 3 u
= 2 u

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

Number of mocha 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 = 192

1 u = 192 ÷ 3.2 = 60

Number of more tarts in Container R than Container S at first
= 9 u - 5 u
= 4 u
= 4 x 60
= 240

Answer(s): 240