Question

There r some student in two examinations halls A and B . To make the number of students equal on each hall , 10 students are sent from A and B . But if 20 students are sent from B to A , the number of the student in A becomes double the number of students in B find the number of the students in two halls.

Answer 1

Answer:

Step-by-step explanation:

Let a and b be the number of students in halls A and B respectively, such that a > b.

Then, if 10 students are transferred from a to b, the number of students are equal.

Therefore, a-10 = b+10

or a - b = 20 ---------- (1)

Similarly, if 20 students are sent from hall B to hall A, then the number of students in Hall A would be twice that of the students in Hall B.

Then, a+20 = 2(b-20)

or a + 20 = 2b - 40

or 2b - a = 60 ------- (2)

Adding equations (1) and (2), we get

2b - a = 60

a - b = 20

Therefore, on adding we get, b = 80

Substituting the value of b = 80 in equation 1, we get

a - 80 = 20

or a = 100.

Therefore there are 100 students in Hall A and 80 students in Hall B.

Hope it helps