Sean School had 690 students and Eric School had 40% less students. When an equal number of students joined each school, the ratio of the students in Eric School to that in Sean School became 3 : 2. How many students were there in both schools in the end?

	Sean School	Eric School	Difference
Before	690		276
Change	+ ?	+ ?
After	3 u	2 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 Sean School and Eric School at first and in the end the same. 

Difference between the number of students in both schools at first
= 40% x 690
= ⁴⁰₁₀₀ x 690
= 276

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

1 u = 276

Total number of students in both schools in the end
= 3 u + 2 u
= 5 u
= 5 x 276
= 1380

Answer(s): 1380