Suppose X and Y Are Random Variables Whose Density Function

Essay

Suppose X and Y are random variables whose density function is given by $f ( x , y ) = \left\{ \begin{array} { l l } 0.2 e ^ { - ( 0.5 x + 0.4 y ) } & \text { if } x \geq 0 , y \geq 0 \\0 & \text { otherwise }\end{array} \right.$ . Find the probability $P ( X \leq 1 , Y \leq 2 )$ .