Question

When spinning a wheel with 1 red, 2 blue, and 3 green spaces, what

is the probability that you will not spin a red?

Answer 1

Explanation:

so, we have 1 + 2 + 3 = 6 total spaces.

a probability is always the ratio

desired cases / totally possible cases

the probability to spin red is therefore

1 desired case

6 total possible cases

1/6 = 0.166666666...

a probability of 1 means a sure result = anyone of the totally possible cases.

so, 6/6 = 1 in our case.

if the desired cases are everything but red, we need to eliminate the possible red results (1) from the amount of our desired cases : 6 - 1 = 5

so the probability of not spinning a red is

5/6 = 0.833333333...

formally we can also say this is the sure thing minus the opposite of what we want to have. the opposite of not spinning a red is spinning a red (1/6) :

1 - 1/6 = 5/6 = 0.833333333...