Sandy spent 1/4 of an hour waiting to see the dentist
Since there are 60 minutes in an hour, we can divide 60 by four to find 1/4 of an hour. 1/4 of an hour is 15 minutes, so sandy spent 15 minutes waiting to see the dentist.
which was 1/6 of the total time she spent at the dentist's office
we know that 15 minutes was 1/6 of the time she spent at the dentist's office, so we can multiply 15 by 6 to find the total amount of time spent.