Suppose that in a population of shoppers, the proportion of people who had visited supermarket A last month is 0.22. Also that in the same population, the proportion of people who had visited supermarket B last month is 0.46. The proportion of shoppers who had visited both supermarket A and supermarket B last month is 0.10.

Question

Suppose that in a population of shoppers, the proportion of people who had visited supermarket A last month is 0.22. Also that in the same population, the proportion of people who had visited supermarket B last month is 0.46. The proportion of shoppers who had visited both supermarket A and supermarket B last month is 0.10. 
What proportion of people in this population had visited supermarket A or supermarket B or both last month? (Give your answer to two decimal places.)

Steve · Accepted Answer

.22 + .46 - .10 = .58