The ratio of the number of cookies in Container M to the number of cookies in Container N was 7 : 5. 40% of the cookies in Container M and 0.6 of those in Container N were mocha. After transferring the cookies between the 2 containers, the number of peach cookies in both containers are the same. Likewise, the number of mocha cookies in both containers are the same. If a total of 216 cookies were moved, how many more cookies were there in Container M than Container N at first?

Container M		Container N
7 u		5 u
Mocha	Peach	Mocha	Peach
2.8 u	4.2 u	3 u	2 u
+ 0.1 u	- 1.1 u	- 0.1 u	+ 1.1 u
2.9 u	3.1 u	2.9 u	3.1 u

Number of mocha cookies in Container M
= 40% x 7 u
= ⁴⁰₁₀₀ x 7 u
= 2.8 u

Number of peach cookies in Container M
= 7 u - 2.8 u
= 4.2 u

Number of mocha cookies in Container N
= 0.6 x 5 u
= 3 u

Number of peach cookies in Container N
= 5 u - 3 u
= 2 u

Number of mocha cookies in each container in the end
= (2.8 u + 3 u) ÷ 2
= 5.8 u ÷ 2
= 2.9 u

Number of peach cookies in each container in the end
= (4.2 u + 2 u) ÷ 2
= 6.2 u ÷ 2
= 3.1 u

Number of cookies moved
= 0.1 u + 1.1 u
= 1.2 u

1.2 u = 216

1 u = 216 ÷ 1.2 = 180

Number of more cookies in Container M than Container N at first
= 7 u - 5 u
= 2 u
= 2 x 180
= 360

Answer(s): 360