Probability - Geometric probability

SOURCE:COMPETITION
Number of Problems: 2. : (Book)

A point $(x,y)$ is randomly picked from inside the rectangle with vertices $(0,0)$ , $(4,0)$ , $(4,1)$ , and $(0,1)$ . What is the probability that $x<y$ ?

$mathrm{(A) } frac{1}{8}qquad mathrm{(B) } frac{1}{4}qquad mathrm{(C) } frac{3}{8}qquad mathrm{(D) } frac{1...$

Two real numbers are selected independently at random from the interval $[-20, 10]$ . What is the probability that the product of those numbers is greater than zero?

$extbf{(A)} frac{1}{9} qquad extbf{(B)} frac{1}{3} qquad extbf{(C)} frac{4}{9} qquad extbf{(D)} frac{5}{9} qq...$