Japheth School had 575 pupils and Simon School had 40% more pupils. When an equal number of pupils left each school, the ratio of the pupils in Simon School to that in Japheth School became 2 : 1. How many pupils were there in both schools in the end?

	Japheth School	Simon School	Difference
Before	575		230
Change	- ?	- ?
After	2 u	1 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 Japheth School and Simon School at first and in the end the same. 

Difference between the number of pupils in both schools at first
= 40% x 575
= ⁴⁰₁₀₀ x 575
= 230

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

1 u = 230

Total number of pupils in both schools in the end
= 2 u + 1 u
= 3 u
= 3 x 230
= 690

Answer(s): 690