Suppose X and Y are random variables with joint density function

Suppose X and Y are random variables with joint density function f(x, y)={0.1 e^-(0.5x+0.2y) if x≥0, y≥0 , 0 otherwise.

Find the following probabilities.
(I) P(Y≥1)
(II) P(X≤2, Y≤4)