A percentage is a fraction whose denominator is 100; for example, 6 percent (written as 6%) is the percentage whose value is $$\frac6{100}$$.
Similarly, 40 as a percentage of 250 is $$\frac{40}{250}\times100=16\%$$.
A percentage is a fraction whose denominator is 100; for example, 6 percent (written as 6%) is the percentage whose value is $$\frac6{100}$$.
Similarly, 40 as a percentage of 250 is $$\frac{40}{250}\times100=16\%$$.