A grade has 81 girls and 72 boys. The grade is split into groups that have the same number ratio of girls to boys as the whole grade. How many girls are In a group that has 16 boys?

There are 18 girls in a group that has 16 boys.

Step-by-step explanation:

Total number of girls

=

81

Total number of boys

=

72

Ratio of girls : boys of whole grade

=

81

:

72

=

9

:

8

The grade is split into groups maintaining same ratio of whole grade ie;

9

:

8

Let the group having

16

boys have

x

girls:

9

8

=

x

16

9

8

*

16

=

x

9

*

2

=

x

x

=

18

girls