OR Probabilities from a Table

Question

The table below shows which hand is favored by each of 100 people (50 men and 50 women). Use the information in the table to determine the probability that someone selected randomly from the group will be female or left-handed.

Left-Handed Right-Handed
Men 8                42
Women 5           45

 

??? (Round to the nearest percent.)

Answer 1

The only way to select someone is NOT either female or left handed is to select a right handed man, which will occur 42% of the time.  So the probability of selecting someone who IS female or left handed is 100% - 42% = 58%.  

 

Note that you can also get the answer by adding up the probabilities that you select a left handed man, a left handed woman, or a right handed woman, which are 8% + 5% + 45% = 58%.