the ratio of boys to girls is 9 to 10. There are 189 boysin the school. How many girls are there?

210

Cross multiply and solve for x.

9/10 = 189/x

To find the number of girls, we can use the given ratio of boys to girls and the number of boys in the school.

First, let's find the total number of parts in the ratio. The ratio of boys to girls is 9 to 10, which means there are 9 + 10 = 19 parts in total.

Next, we can find the value of each part by dividing the total number of boys by the number of parts for boys: 189 boys / 9 parts = 21 boys per part.

Finally, we can find the number of girls by multiplying the number of parts for girls by the value of each part: 21 boys per part * 10 parts = 210 girls.

Therefore, there are 210 girls in the school.

To find the number of girls, we need to determine the ratio of boys to girls. According to the given information, the ratio of boys to girls is 9 to 10.

We know that there are 189 boys in the school. We can use this information to find out how many girls there are.

First, we need to determine the total ratio (boys + girls). In this case, the total ratio is 9 + 10 = 19.

We can then calculate the fraction of the total ratio that represents the number of boys by dividing the number of boys (189) by the total ratio (19). This gives us 189/19 = 9.

Now that we know the fraction representing the number of boys, we can find the fraction representing the number of girls by subtracting this fraction from 1. So, 1 - 9/19 = 10/19.

Finally, to find the number of girls, we multiply the fraction representing the number of girls (10/19) by the total number of students in the school. Since we don't have the total number of students, we can't determine the exact number of girls. However, we can find a proportional value.

If we assume that the total number of students is a multiple of 19 (the denominator of the fraction representing the total ratio), we can calculate the number of girls as follows:

Number of girls = (10/19) * Total number of students

For example, if we assume that the total number of students is 190 (a multiple of 19), we can find the number of girls as (10/19) * 190 = 100.

Therefore, the number of girls would be 100 if the total number of students is 190.