Question

At a country concert, the ratio of the number of boys to girls is 2:7. If there are 250 more girls than boys, how many boys are at the concert? PLZ HELP

Answer 1

We can setup an equation for this.

Boys to Girls = 2:7
Boys = x
Girls = 250+x
Setup the ratio
x:(250+x) = 2:7
x / (250+x) = 2/7
7x = 500+2x
7x-2x = 500
x = 500/5 =100

There are 100 boys at the concert

Answer 2

100 boys at the concert

Explanation:

At a country concert, the ratio of the number of boys to girls is 2:7

Let 'b' be the number of boys in the concert

there are 250 more girls than boys

so b+250 are the number of girls in the concert

the ratio of boys to girls is b: b+250

Now make a proportion using the ratio

`(2)/(7) =(b)/(b+250)`

Now solve for b . cross multiply the fraction

`(b+250) \cdot 2= 7 \cdot b`

`2b+500= 7b`

Subtract 2b from both sides

`5b= 500`

Divide both sides by 5

b=100

So there are 100 boys at the concert