Jenson School had 790 pupils and Fred School had 10% more pupils. When an equal number of pupils left each school, the ratio of the pupils in Fred School to that in Jenson School became 4 : 3. How many pupils were there in both schools in the end?

	Jenson School	Fred School	Difference
Before	790		79
Change	- ?	- ?
After	4 u	3 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 Jenson School and Fred School at first and in the end the same. 

Difference between the number of pupils in both schools at first
= 10% x 790
= ¹⁰₁₀₀ x 790
= 79

Difference between the number of pupils in both schools in the end
= 4 u - 3 u
= 1 u

1 u = 79

Total number of pupils in both schools in the end
= 4 u + 3 u
= 7 u
= 7 x 79
= 553

Answer(s): 553