Question : There are some students in two examination halls A and B. To make the number of students equal in each hall, 10 students are sent from A to B. But if 20 students are sent from B to A, the number of students in A becomes double the number of students in B. Find the number of students in two halls.
Doubt by Ananya
Solution :
Let the number of students in Hall A = x
and the number of students in Hall B = y
ATQ
x-10 = y+10
x-y = 10+10
x-y = 20 ---------(1)
Also,
x+20 = 2(y-20)
x+20 = 2y-40
x-2y = -40-20
x-2y = -60 --------(2)
Solving eq (1) and (2) by elimination method.
x - y = 20
x - 2y = -60
- + +
--------------------
0 + y = 80
--------------------
y = 80
putting in equation (1)
x - y = 20
x-80 = 20
x= 80 + 20
x=100
Therefore,
No. of Students in Hall A = 100
No. of Students in Hall B = 80
Similar Question :
If 10 students are transferred from section A of a class to section B, the number of students in each section become equal. But if 10 students are transferred from section B to section A, the number of students in section A becomes three times that of section B. Find the number of students in each section.