Half the numbers from $1$ to $40$ are greater than $20$, Thus, the probability of choosing numbers greater than $20$ is $\dfrac{1}{2}$. 
The numbers from $1$ to $40$ are written on $40$ pieces of paper, respectively, and put into a box. A piece of paper is chosen at random. Find the probability of choosing a number greater than $20$. 
a) $$\frac{1}{2}$$ 
b) $$\frac{1}{3}$$ 
c) $$\frac{1}{4}$$ 
d) $$\frac{2}{5}$$ 