Harry School had 720 pupils and Xavier School had 25% more pupils. When an equal number of pupils left each school, the ratio of the pupils in Xavier School to that in Harry School became 3 : 2. How many pupils were there in both schools in the end?

	Harry School	Xavier School	Difference
Before	720		180
Change	- ?	- ?
After	3 u	2 u	1 u

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

Difference between the number of pupils in both schools at first
= 25% x 720
= ²⁵₁₀₀ x 720
= 180

Difference between the number of pupils in both schools in the end
= 3 u - 2 u
= 1 u

1 u = 180

Total number of pupils in both schools in the end
= 3 u + 2 u
= 5 u
= 5 x 180
= 900

Answer(s): 900