In a school,the ratio of boys to girls is 9:4.If there are presently 720 girl students,how many more girls would it take to reduce the ratio of boys to girls to 2:1?
720/4 = 180
so,
9:4 = 1620:720
Now, 1620 = 2*810
so, you need to add 810-720 = 90 girls
To solve this problem, we need to find the number of boys in the school, and then determine how many more girls are needed to achieve a ratio of 2 boys to 1 girl.
Given that the ratio of boys to girls is 9:4, we can set up the following proportion:
9 boys / 4 girls = x boys / 720 girls
To find the number of boys, we solve for x:
9/4 = x/720
Cross-multiply:
4x = 9 * 720
4x = 6480
x = 6480 / 4
x = 1620
So, there are currently 1620 boys in the school.
To achieve a ratio of 2 boys to 1 girl, we need the number of girls to be half the number of boys. So, we can calculate the desired number of girls:
Number of girls = (1/2) * Number of boys
Number of girls = (1/2) * 1620
Number of girls = 810
Since there are currently 720 girls in the school, we need an additional:
810 - 720 = 90
It would take 90 more girls to reduce the ratio of boys to girls to 2:1.