help asap with probability problem 9 a,b

9. Household incomes in a certain region are uniformly distributed between $0 and $60,000. Households with incomes below $30,000 pay no income tax; households with incomes above $30,000 pay no tax over the first $30,000, but pay 20% tax over the remainder of their income. Let X be the amount of tax paid by a randomly selected household. a) ( 6 pts.) Find the c.d.f. of X, and sketch its graph. b) (5 pts.) Find E(X). Explain your reasoning