What is the probability of spinning blue or green

Question

Write as decimal 

red:2

yello:3

green:2

blue:1

Answer 1

Assuming the wheel can not end up on two colors (the line between two colors) there are 4 possible outcomes and if the wheel is "fair" there is a equal chance that any color will be chosen. So for any color there is a 1 in 4 chance of the result being a certain color (1 in 4 = 1/4 = 0.25).  Since you are looking for either blue or green, the chances are the sum of the individual probabilities or 0.25+0.25=0.5.

 

Another way to look at the problem is that any two colors take up 1/2 the wheel's surface so the chances of the wheel landing on one of these colors is 50% or 0.5.

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