Answer
$50$.
Work Step by Step
The equation: $0.1x(300-x)=1250\\x(300-x)=12500\\-x^2+300x-12500=0\\x^2-300x+12500=0\\(x-150)^2=10000$.
If we take the square root of both sides we get:$x-150=\pm100$. Thus $x=250$ or $x=50$, but we know that $x$ is at most $200$, thus the answer is $50$.
