Elevator Mechanic Practice Exam

How many Position Indicators (P.I.) are needed for a 12-stop building with 3 cars, if 3 floors do not have Position Indicators?

1. 18

2. 24

3. 27

4. 33

The correct answer is: 18

For a 12-stop building with 3 cars, each car has the ability to stop at 12 different floors. This means that there are 36 possible stops (12 floors x 3 cars). However, the question specifies that 3 floors do not have Position Indicators (P.I.), meaning the cars will not stop at these floors and therefore do not need P.I.s. This leaves us with a total of 33 floors that require P.I.s. Since each car only needs one P.I., we can calculate the total number of P.I.s needed by multiplying the number of cars (3) by the number of floors (33), resulting in 99 P.I.s. However, since 3 floors do not have any P.I.s, we subtract 3 from 99, giving us our final answer of 96 P.I.s necessary for this 12-stop building with 3 cars. Therefore, option A is the correct answer. Options B, C, and D are incorrect as they do not reflect the fact that 3 floors do not need P.I.s.