Posted by **Vickie** on Thursday, January 14, 2010 at 11:02pm.

The number of girls in a class is 70% of the number of boys. If the class has 25 boys, how many girls are in the class?

- 6th grade Math -
**Writeacher**, Friday, January 15, 2010 at 9:50am
You can set up a ratio and then cross multiply.

http://www.worldplenty.com/rat.htm#topic7

25/x = 0.3

That is, 25 boys over x (which stands for the total number of students in the class) = 30% (shown as 0.30 for multiplying purposes).

When you cross multiply (see the webpage I gave you above), you should get 83, the total number of students.

Now you know the number of boys (25) and the total number of students (83). Subtract the boys from the class total to find the number of girls in the class. What do you get?

## Answer This Question

## Related Questions

- algebra - Classes A and B have 35 students each. If seven girls shift from class...
- algebra - Classes A and B have 35 students each. If seven girls shift from class...
- math - There are 27 students in Mrs. Reeds class. The number of boys and number...
- math - There are 24 students in Mr.Hills class. The number of boys and number of...
- mathematics - there are 5 more girls than boys in a class. if 2 boys join the ...
- math - In a class of 80 seniors, there are 3 boys for every 5 girls. In the ...
- Maths - There are 40 pupils in a class. There are 10 more boys than girls. When ...
- math - There are 12 girls in one of the fifth grade classes. The number of girls...
- MATHS - Class A and Class B have the same number of pupils. The ratio of the ...
- Math - Mrs.Smith's class has 12 girls and 8 boys. What percent of he class are ...

More Related Questions