Basic Probability Statistics Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
A bag contains 3 red, 5 blue, and 2 green marbles. What is the probability of drawing a blue marble?

Solution

  1. 1
    Step 1: Total marbles = 3+5+2=103 + 5 + 2 = 10.
  2. 2
    Step 2: Favourable outcomes (blue) = 5.
  3. 3
    Step 3: P(blue)=510=12P(\text{blue}) = \frac{5}{10} = \frac{1}{2}.

Answer

12\frac{1}{2}
Basic probability is the ratio of favourable outcomes to total possible outcomes, assuming each outcome is equally likely.

About Basic Probability

Probability is the measure of how likely an event is to occur, expressed as a number between 0 (impossible) and 1 (certain). It is calculated as the ratio of favorable outcomes to total possible outcomes when all outcomes are equally likely.

Learn more about Basic Probability →

More Basic Probability Examples

Example 2 easy

A fair six-sided die is rolled. What is the probability of rolling an even number?

Example 3 easy

A spinner has 8 equal sections numbered 1–8. What is the probability of landing on a number greater

Example 4 easy

A card numbered 1 through 10 is chosen at random. What is the probability that the number is prime?

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