Arestaurant chain’s owners are trying to decide if they want to open up a franchise in your town. to
them decide, they want to find out how often people in your town go out to eat. a researcher
interviews people leaving a local restaurant. is there a bias in this sampling method? explain. (

Yes. There is bias in this sampling method.

Let's break the question down.

Restaurant chain: place to buy FOOD
franchise in your town: PLACE they want to open a restaurant
want to find out how often people in your town go out to eat: the question
a researcher: guy interviewing people
interviews people leaving a local restaurant: NON-random people being interviewed

the problem here is that people want to open a RESTAURANT. And if you interview people leaving a RESTAURANT, there's bias because the people just ate there. The owners must interview random people in town.