Sarah's coffee house is open each weekday for 12 hours . This means on week days which are Monday, Tuesday, Wednesday, Thursday and Friday she opens her coffee shop for 12 hours each day . Then on weekends she opens her shop for twice as long . This means she opens her shop 2 times the time she usually opens (12 hours).
it can be computed mathematically as
2 × 12 hours = 24 hours.
Since she opens her shop for 12 hours on week days, twice the hours she spent on weekend is 12 × 2 = 24 hours.
Note that the question asked how long she opens on Saturday. Saturday and Sunday are weekend. Since the information of how long she open on weekends is known, that means how long she opens on Saturday which is regarded as weekend can be computed.
