Reggie School had 540 students and Peter School had 40% less students. When an equal number of students joined each school, the ratio of the students in Peter School to that in Reggie School became 5 : 4. How many students were there in both schools in the end?

	Reggie School	Peter School	Difference
Before	540		216
Change	+ ?	+ ?
After	5 u	4 u	1 u

Since an equal number of students joined each school, the difference in the number of students at first and in the end between the 2 schools remains the same.  Make the difference between the number of students in Reggie School and Peter School at first and in the end the same. 

Difference between the number of students in both schools at first
= 40% x 540
= ⁴⁰₁₀₀ x 540
= 216

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

1 u = 216

Total number of students in both schools in the end
= 5 u + 4 u
= 9 u
= 9 x 216
= 1944

Answer(s): 1944