Question

2/3 of miss lina's class were boys. there were between 2 and 14 boys. One day, twin girls joined the class. Now 3/5 of the students are boys. how many students are in miss lina's class now?

Answer 1

If there were originally b boys out of s students in the class,

b/s = 2/3
b/(s+2) = 3/5

Or,

b = 2s/3
5b = 3s+6

So,

5(2s/3) = 3s+6
10s = 9s+18
s = 18

Now you should be able to answer the question.