Grade 6 Statistics: Basic Probability

Worked examples

Real problems from the practice worksheets, solved one step at a time.

1. Example 1

   A spinner has 12 equal sections: 4 green, 3 yellow and 5 red. You spin it once. What is the probability of landing on red?

   1. Total outcomes: count everything that could happen, 4 + 3 + 5 = 12.
   2. Favorable outcomes: the 5 red.
   3. Probability = favorable ÷ total = 5/12.
   4. So the probability is 5/12.

   Answer: 5/12

2. Example 2

   A bag has 6 blue and 1 purple marbles. You pick one marble without looking. What is the probability of picking purple?

   1. Total outcomes: count everything that could happen, 6 + 1 = 7.
   2. Favorable outcomes: the 1 purple.
   3. Probability = favorable ÷ total = 1/7.
   4. So the probability is 1/7.

   Answer: 1/7

3. Example 3

   A bag has 8 green, 3 yellow, 7 purple and 4 blue marbles. You pick one marble without looking. What is the probability of picking green?

   1. Total outcomes: count everything that could happen, 8 + 3 + 7 + 4 = 22.
   2. Favorable outcomes: the 8 green.
   3. Probability = favorable ÷ total = 8/22, which simplifies to 4/11.
   4. So the probability is 4/11.

   Answer: 4/11