Glen School had 340 pupils and Michael School had 10% more pupils. When an equal number of pupils left each school, the ratio of the pupils in Michael School to that in Glen School became 5 : 4. How many pupils were there in both schools in the end?

	Glen School	Michael School	Difference
Before	340		34
Change	- ?	- ?
After	5 u	4 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 Glen School and Michael School at first and in the end the same. 

Difference between the number of pupils in both schools at first
= 10% x 340
= ¹⁰₁₀₀ x 340
= 34

Difference between the number of pupils in both schools in the end
= 5 u - 4 u
= 1 u

1 u = 34

Total number of pupils in both schools in the end
= 5 u + 4 u
= 9 u
= 9 x 34
= 306

Answer(s): 306