To gain insight into the last exercise, use your intuition to sketch the PDFs of:

a. a U(–10, 10) random variable;

b. a sum of a U(–10, 10) and 1 independent U(–1, 1) random variables;

c. a sum of a U(–10, 10) and 2 independent U(–1, 1) random variables;

d. a sum of a U(–10, 10) and 3 independent U(–1, 1) random variables.