Question

There are 40 children in class. 16 of them are girls. How many percent more boys than girls are there?

Answer 1

Total no of children = 40
No of girls = 16
.·. No of boys = (40-16) = 24

Now,
% of girls present = $\frac{16}{40}$ × 100 = 40%

% of boys present = $\frac{24}{40}$ × 100 = 60%

.·. % of boys more than girls = (60-40)% = 20%

Answer: 20% of boys are more than girls.

Answer 2

Number of children = 40
number of girls = 16
number of boys = 40-16= 24
to calculate percentage of boys in the class -- 24/40*100 = 60%
Percentage of girls = 40% 
difference in percentage =60-40=20
hence when compared to the number of girls , boys are 20% more in number.