40. The difference equals the quotient. Find two numbers whose difference and quotient are both equal to 5.
40. Since the quotient of two numbers is 5, the difference between them is four times the smaller one. Therefore, the smaller number is $\frac{5}{4}$, and the larger one is $\frac{25}{4}$.

In the general case if $x-y=\frac{x}{y}=a$, then

$$
x=\frac{a^{2}}{a-1}, \quad \text { and } \quad y=\frac{a}{a-1}
$$