Please show me how to solve the following include the steps

Please show me how to solve the following, ***include the steps**** also, please!

1. Let X and Y be Bernoulli random variables as follows
    P(X = 1) = 1/4
    P(Y = 1 | X = 0) = 1/3
    P(Y = 1 | X = 1) = 1/5
    and a defining Z as Z = X + Y

a) Find E(Z) using the following two method
    1. E(Z) = E(X) + E(Y)
    2. E(Z) = (0)P(Z=0) + (1)P(Z=1) + (2)P(Z=2)

b) Find E(5Z)

c) Find E(X^3)

d) Find E(W^2)

Thank you!

Solution

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page 1 = https://drive.google.com/file/d/0B6-y3LStajLMa1dlMnM3U01IMUsxN25pLXo1OTAxYUVobDNv/view?usp=sharing

page2= https://drive.google.com/file/d/0B6-y3LStajLMdGVneTh1cFJxZmd6UWlSNGVGNTVIWjJYVGtj/view?usp=sharing