GED Practice

GED Math Review: Probability




  1. On an afternoon TV game show, contestants can choose one of ten prizes, numbered 1 through 10, sight unseen. Five of the prizes are almost worthless (for example, toilet bowl cleaner), two are worth $100, two are worth $1,000, and the grand prize is a new car. What is the chance that the ninth contestant will win the car?
    • 1/2
    • 9/10
    • 4/5
    • 1/10
  2. Consider a pair of dice, which are six sided cubes with a number from 1 to 6 on each side. If we tossed them as a pair, what is the probability that the total shown will be between 2 and 12?
    • 10%
    • 25%
    • 50%
    • 100%
  3. Getting head on the flip of a coin, what is its probability?
    • 1/2 or 50%
    • 1/4 or 25%
    • 1/1 or 100%
    • 3/5 or 60%
  4. Suppose you have a jar containing 20 marbles. Eight of them are red, 7 are yellow, and 5 are blue. Now if you choose a marble from the jar, without looking so it is a random pick, which probability would be true that a yellow marble is picked?
    • 7/20 or 35%
    • 5/20 or 25%
    • 8/20 or 40%
    • 15/20 or 75%
  5. Suppose you have a jar containing 20 marbles. Eight of them are red, 7 are yellow, and 5 are blue. Let's now consider two picks and the probability of picking a red marble on the first pick and a yellow one on the second pick. What is the probability of red and yellow on two picks?
    • 14%
    • 28%
    • 42%
    • 56%

Answers:

  1. 1/10 
    1 favorable event out of ten possible events
  2. 100%
  3. 1/2 or 50%
  4. 7/20 or 35%
  5. 8/20 x 7/20 = 56/400 or 14%




Reference:
GED Math Test Tutor by Sandra Rush