Restaurant owners have to know how to make food．They 1 have to know how to make money．Here are some things they’ve learned from 2 studies．The color red 3 people hungry．Red also makes customers 4 faster．Many fast food restaurants, 5 , have red furniture or walls．Soft colors like pink and light blue make people 6 , so they spend more time 7 their meals．Soft lighting makes people look good, but it makes food look bad．Loud music may be nice 8 , but it soon makes people want to leave．Hard seats also make customers want to eat quickly and leave．Many restaurants, especially fast food restaurants, use this knowledge to make customers eat faster．Customers only sit for about 20 minutes 9 they leave．Because customers don’t stay very long, small restaurants can 10 many people every day．