At the country concert, the ratio of boy to girls = 2
: 7
Now, there are 250 more girls than boys, how many boys are there in the concert.
the equation would be like this:
Let x = girls
Let y = boys
=> y /x = 2/7
=> y + 250 = x
=> y + 250 = 7/2y
=> y = 100
The number of boys is 100
=> x = 100 + 250
=> x = 350, the number of girls.