Respuesta :

Answer:

15 boys

Step-by-step explanation:

Whatever number one side of the ratio is multiplied by, the other side has to be multiplied by that same number. So, we have to find the number that 4 is multiplied by to get 20. We can represent this as an equation, where the unknown number is x:

4x = 20

Divide both sides of the equation by 4 to find the value of x:

x = 5

4 was multiplied by 5 to get 20.

To find the number of boys, multiply 3 by 5:

3 * 5 = 15

If there are 20 girls, there will be 15 boys.