Question

* 24% of students in a class are girls. If there are less than 30 students in this class, how many students are there? How many girls are there?

Answer 1

8

Explanation:

Make a proportion: 24/100 = x/30. Now you need to find x. You could simplify 100 and 30 since they have a common factor of 10. 100/10=10 and 30/10=3. So now you have 24/10 = x/3. Now it is easier to cross multiply. Once you cross multiply you would get 7.2. You cant have 7.2 girls so round to 8.

Answer 2

25 students

6 girls

Explanation:

The problem can be solved by calculating the greatest common factor (GCF) between 24 and 30 (since it is 24% and less than 30 students).

For 24:

1x24

2x12

3x8

4x6

Factors of 24 = 1,2,3,4,6,8,12,24

For 30:

1x30

2x15

3x10

5x6

Factors of 30 = 1,2,3,5,6,10,15,30

GCF = 6

Then, we can conclude that 30/6 is the fraction of reduction which must be subtracted from 30, so to know how many students there are we apply the following formula:

30 - 30/6 = 30 - 5 = 25

The number of girls is calculated as follows:

25 x 24% = 25 x 0.24 = 6

In summary, there are 25 students, of which 6 are girls

Hope this helps!