Cole School had 690 pupils and Harry School had 30% more pupils. When an equal number of pupils left each school, the ratio of the pupils in Harry School to that in Cole School became 3 : 2. How many pupils were there in both schools in the end?

	Cole School	Harry School	Difference
Before	690		207
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 Cole School and Harry School at first and in the end the same. 

Difference between the number of pupils in both schools at first
= 30% x 690
= ³⁰₁₀₀ x 690
= 207

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

1 u = 207

Total number of pupils in both schools in the end
= 3 u + 2 u
= 5 u
= 5 x 207
= 1035

Answer(s): 1035