At a local preschool, there is a ratio of 3 boys to every 4 girls. if there are 245 total preschoolers enrolled, how many boys are there

A ratio can be written in three different ways: 3 to 4, 3:4, and 3/4

What does this mean? It means that for every group of 7 students (3+4) there are 3 boys and 4 girls. And how many groups do we have? We have:

245/7= 35 We have 35 groups, and we just said that each group has 3 boys and 4 girls:

35*3= 105 boys

35*4= 140 girls

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Total: 245 students

Here's how to set up an equation:

Let's call the number of girls x. Since the total is 245 students, 245-x= boys:

Set up the equation by writing the number of students in the ratio as a fraction:

3/4= (245-x)/x Cross multiply:

3x= 4(245-x) Multiply on right:

3x= 980-4x Add 4x on both sides:

7x= 980 Divide both sides by 7:

x= 140 this is how many girls there are. And:

245-140= 105= boys

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.