Question

The total number of students in class A and class B is 120. If 15 students from class A are taken and added to class B, the number in class B becomes twice that of A. Find out the number of students in class A in the beginning

Answer 1

Answer:

40

Step-by-step explanation:

Answer 2

Answer: There were 45 students in class A in the beginning.

Step-by-step explanation:

This can be solved as follows-

Total number of students in class A and B = 120

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

After 15 students from A are sent to B,

y= 2x

Also it can be written as:

y+15 = 2x

or, y= 2x-15 ------i

Again, as per the previous equation,

x + y = 120

Placing value of y from i,

x + 2x-15 = 120

or, 3x = 135

or, x= 135/3 = 45

Therefore, there were 45 students in class A in the beginning.