Classes A and B have 35 students each. If seven girls shift from class A to class B, then the number of girls in the classes would interchange. If four girls shift from class B to class A, then the number of girls in class A would be twice the original number of girls in class B. What is the number of boys in class A and class B?

Question

Please help. I'm not able to form a correct equation to solve.

Answer 1

If A has a girls and B has b girls, then we are told:

a-7 = b
a+4 = 2b
So,
a=18
b=11

That means that A had 17 boys and B had 24 boys