Mark School had 365 pupils and Michael School had 40% less pupils. When an equal number of pupils joined each school, the ratio of the pupils in Michael School to that in Mark School became 5 : 4. How many pupils were there in both schools in the end?

	Mark School	Michael School	Difference
Before	365		146
Change	+ ?	+ ?
After	5 u	4 u	1 u

Since an equal number of pupils joined 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 Mark School and Michael School at first and in the end the same. 

Difference between the number of pupils in both schools at first
= 40% x 365
= ⁴⁰₁₀₀ x 365
= 146

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

1 u = 146

Total number of pupils in both schools in the end
= 5 u + 4 u
= 9 u
= 9 x 146
= 1314

Answer(s): 1314