Is this correct?

1). X and Y are independent standard exponential random variables with $\displaystyle \lambda$ = 1

(a) Find $\displaystyle P(X\geq4, Y<3)$

I did $\displaystyle P(X\geq4, Y<3) = P(X\geq4)P(Y<3) = e^{-4}e^{-3} = e^{-7}$

(b) Find $\displaystyle E(X^2Y)$

I am unsure about this. Any help?

(2) A random point (X,Y) is distributed uniformly on the square with vertices (1,1), (1,-1), (-1,1), and (-1,-1). The joint pdf is $\displaystyle f(x,y)=1/4$ on the square.

(a) Find $\displaystyle P(X^2 + Y^2 < 1)$

(b) Find $\displaystyle P(2X - Y > 0)$

If someone can just teach me how to do one of the above in (2), I think I can handle the other. Thank you!!