You need to represent the number of males in terms of females.
Explanation:
Since you know the number of males relative to females, it makes sense to represent the number of females as a variable, let's say f.
So then the number of males is <span>f+240</span> and we know that the number of males plus the number of females is 2500. Knowing this, we can write an equation: <span>f+<span>(f+240)</span>=2500</span>. I put the number of males in brackets there just to make it easy to recognize.
This equation can be condensed into <span>2f+240=2500</span> and then solved:
<span>2f=2500−240</span>
<span>f=<span><span>2500−240</span>2</span></span>
<span>f=1130</span>
Then, we know the number of females, and we can solve for the number of males from here using our male formula: <span>males=f+240</span>. You should then get 1370 as the number of males.
Checking this answer, we see that 1130 + 1370 does equal 2500.
