Answer to Question #225728 in Statistics and Probability for Pirocudo Jr.

Question

At the start of any day, the amount of alcohol in a tank, in many liters, is a
random quantity Y, of which a random quantity X is sold during the day.
tank doesn't refuel during the day, so x ≤ y, and imagine also that a function of
joint density of these variables are:

f(x, y) = 4xy, 0 <x< 1, 0 <y< 1,
0, elsewhere.

Calculate: 𝑃 (1/4 < 𝑋 < 1/2|𝑌 = 3/4)