SAT Math Question of the Day

Math Category: Probability:

Q: Jake has 9 red marbles, 5 blue marbles, 3 green marbles, and 8 orange marbles in a cloth sack. If Jake pulls out 1 marble at random, what is the probability that it will not be red or green?

  1. 11/25
  2. 12/25
  3. 13/25
  4. 14/25
  5. 12/13

UNANSWERED.

The correct answer is C.

A: The answer is 13/25. Probability is outcomes wanted / all outcomes. Read this problem carefully because it asks about marbles that are not red or green... so we add up the orange and blue marbles: 8 + 5 = 13 marbles. So there are 13 ways to get the outcome we want. There are 25 marbles (9 red marbles + 5 blue marbles + 3 green marbles + 8 orange marbles) in the cloth sack. So if a random marble is pulled out, then it could be any of those 25 marbles. The probability is outcomes wanted / all outcomes = 13/25.