The odds of pulling a red ball out of a bag of 30 balls in which 10 are red can be calculated as follows:
First, we need to determine the total number of possible outcomes, which is the number of balls in the bag:
Total number of possible outcomes = 30
Next, we need to determine the number of favorable outcomes, which is the number of red balls in the bag:
Number of favorable outcomes = 10
Therefore, the odds of pulling a red ball out of the bag can be expressed as:
Number of favorable outcomes / Total number of possible outcomes
= 10/30
= 1/3
So the odds of pulling a red ball out of the bag are 1 in 3 or 1/3.