.
The number of customers waiting inside a restaurant was 2 less than a third of those waiting outside.
If 3 customers were waiting inside, how many were outside?
~~~~~~~~~~~~
Number of customers waiting inside is 3.
A third of those waiting outside is 2 more than 3, i.e. 3 + 2 = 5.
Hence, the total number of those waiting outside is 3*5 = 15 persons.
Solved.