Q: An event has 18 more boys than girls. The total number of participants is 1000. How many boys & girls competed?
A: Let B represent the number of “boys” and let G represent the number of “girls”.
We know that there are 18 more boys than girls, so:
(1) G + 18 = B.
We also know that there are a total of 1000 people, so:
(2) G + B = 1000.
Now, from equation (1) we have that B = G + 18 and we can substitue that into equation (2) like so:
G + B = 1000 and plug in (G + 18) for B to get:
G + (G+ 18) = 1000
And solve:
G + (G+ 18) = 1000
2G + 18 = 1000
2G = 982
G = 491.
There are 491 girls. Since there are 1000 total people, we know that 1000 – 491 = 509. There must be 509 boys.