pls explanation is needed. thanks

revious Problem Problem List Next Problem points) A bag contains two 20-dollar bills, three 10-dollar bills, and two 5-dollar bills. Three bills are selected from the bag at random, Let the random variable X represent the total ollar value of the selected bills. That is the least possible value of X? What is the greatest possible value of X? What is Pr(X - 30)? I Enter your answers as whole numbers or fractions in lowest terms. Your answers should all be numeric - do not use dollar signs in your answers