Mark School had 320 students and Ryan School had 40% more students. When an equal number of students left each school, the ratio of the students in Ryan School to that in Mark School became 2 : 1. How many students were there in both schools in the end?

	Mark School	Ryan School	Difference
Before	320		128
Change	- ?	- ?
After	2 u	1 u	1 u

Since an equal number of students left each school, the difference in the number of students at first and in the end between the 2 schools remains the same.  Make the difference between the number of students in Mark School and Ryan School at first and in the end the same. 

Difference between the number of students in both schools at first
= 40% x 320
= ⁴⁰₁₀₀ x 320
= 128

Difference between the number of students in both schools in the end
= 2 u - 1 u
= 1 u

1 u = 128

Total number of students in both schools in the end
= 2 u + 1 u
= 3 u
= 3 x 128
= 384

Answer(s): 384