Seth School had 390 pupils and Ryan School had 40% less pupils. When an equal number of pupils joined each school, the ratio of the pupils in Ryan School to that in Seth School became 4 : 3. How many pupils were there in both schools in the end?
|
Seth School |
Ryan School |
Difference |
Before |
390 |
|
156 |
Change |
+ ? |
+ ? |
|
After |
4 u |
3 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 Seth School and Ryan School at first and in the end the same.
Difference between the number of pupils in both schools at first
= 40% x 390
=
40100 x 390
= 156
Difference between the number of pupils in both schools in the end
= 4 u - 3 u
= 1 u
1 u = 156
Total number of pupils in both schools in the end
= 4 u + 3 u
= 7 u
= 7 x 156
= 1092
Answer(s): 1092