How many shoppers didnt own a car or a house? -

of the 500 shoppers interviewed at a local mall, 50% were homeowners and 75% owned at least one car .if 240 of the shoppers were both homeowners and car owners,then how many shoppers didn t own a house or a car?

I don t see a question here about Small Business. Please advise on the relevance of this question to Small Business issues so that I might be able to help you...