in the 6th grade classes there for girls for every 3 boys it's are 24 girls how many boys are there

18 boys

Step-by-step explanation:

The Ratio of girls to boys is 4:3. To get the girls (ratio part 4) to 24 you would multiply some number times 4 to get to 24. since 6 can go into 24 four times, that means the girls multiplied by 6. Now the girls can't just multiply and not the boys, so the boys (ratio part 3) have to be multiplied by 6 as well. This means the first part of the ratio is 24 and the second part is 18. So the ratio is 24:18. the second part of the ratio shows boys, so there are 18 boys.