Probability word problems
The question
What is the probability that it is NOT green? Write your answer in simplest form.
A jar has 8 green beads and 4 blue beads. One bead is picked at random.
12 altogether
not green → 4
4 out of 12
- Read it through. A probability is how many outcomes you want, over how many there are altogether.
- Count the whole set first — that is the bottom number: 12 altogether.
- Now the top. The question asks for "not green", so it is everything else. Take them off the total: that leaves 4.
- Write the top over the bottom: 4 over 12, then simplify — .
How it works.
- 01
Read it through. A probability is how many outcomes you want, over how many there are altogether.
- 02
Count the whole set first — that is the bottom number: 12 altogether.
- 03
Now the top. The question asks for "not green", so it is everything else. Take them off the total: that leaves 4.
- 04
Write the top over the bottom: 4 over 12, then simplify — 1/3.