This one is actually prety easy. It takes twelve seconds to go up three floors, from floor 1 to floor 4. With this knowledge, we know that the elevator takes about 4 seconds to move up a floor.
Now to calculate the time to move from floor 14 to floor 38, we need to know how many floors are in between, so we subtract 38 - 14 which is 24.
The last step is to multiply 24 floors by 4 seconds for each floor. Which results in an answer of a total 96 seconds.