In a class, there were more than 10 boys and a certain number of girls. After 40% of the girls and 60% of the boys left the class, the remaining number of girls was 8 more than the remaining number of boys. Then, the minimum possible number of students initially in the class was

Let say number of girls be $$g$$ and number of boys be $$b$$.

If 40% of the girls left, remaining number of girls = $$0.6g$$

Also if 60% of the boys left, remaining number of boys = $$0.4b$$

or, $$0.6g=0.4b+8$$

or, $$6g=4b+80$$

or, $$3g=2b+40$$

So, the possible values of (b,g) are: (13,22),(16,24),(19,26),(22,28),(25,30),.....

Now, $$0.6g$$ and $$0.4b$$ has to be an integer.

So, for this $$g$$ and $$b$$ has to be a multiple of 5

So, $$b=25$$ and $$g=30$$

So, minimum possible number of students = $$25+30=55$$