# Need math help with two examinations rooms

label Mathematics
account_circle Unassigned
schedule 1 Day
account_balance_wallet \$5

There are two examinations rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is

Jan 3rd, 2016

Let the number of students in Room A be x and the number of students in Room B be y.

If 10 students are sent from A to B then the number of students in A=x-10

and in Room B the number of students =y+10

Given each room the number of student is same,x-10=y+10 =>x=y+20 ---eqn(1)

If 20 candidates are sent from B to A

then the number of student in A=x+20

In B the number of student =y-20

Given,x+20=2(y-20)

x+20=2y-40

x=2y-60  ---eqn(2)

Solove both the equation using substitution

Substitute the value of x from eqn(1) in eqn(2) we get

2y-60=y+20

y=80 and x =2*80-60 =>x=100

Thus the number of student in Room A=100 (answer)

I hope this would help you,but if you have any doubt regarding this,you can surely ask. :)
Jan 3rd, 2016

...
Jan 3rd, 2016
...
Jan 3rd, 2016
Nov 18th, 2017
check_circle