Ian School had 788 students and Carl School had 25% less students. When an equal number of students joined each school, the ratio of the students in Carl School to that in Ian School became 5 : 4. How many students were there in both schools in the end?

	Ian School	Carl School	Difference
Before	788		197
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 Ian School and Carl School at first and in the end the same. 

Difference between the number of students in both schools at first
= 25% x 788
= ²⁵₁₀₀ x 788
= 197

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

1 u = 197

Total number of students in both schools in the end
= 5 u + 4 u
= 9 u
= 9 x 197
= 1773

Answer(s): 1773