Question

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

Answer 1

`2x-number\ of\ boys\\7x-number\ of\ girls\\\\7x=2x+250\\7x-2x=250\\5x=250\\x=50\\\\2x=2\cdot50=100\\\\There\ are\ 100\ boys\ at\ the\ concert.`