## Basic College Mathematics (10th Edition)

To determine how many rings are sold in 30 days, you must first determine how many minutes are in 30 days. There are 24 hours in one day, so in 30 days there are $24 \times 30 = 720$ hours. There are 60 minutes in one hour, so in 720 hours there are $60 \times 720 = 43200$ minutes. Since one ring is sold per minute, 43,200 rings are sold in 30 days.