An elevator goes up 3 floors, then down 1 floor repeatedly. Starting from floor 0, when does it first reach floor 10?

After 6 cycles. Net gain is 2 per cycle. After 4 cycles it's at 8, in the 5th cycle it reaches 11, so it reaches 10 during cycle 5, meaning after 4 full cycles completed.

Why do 'skip logic' elevator puzzles usually trick people?

They hide a stopping condition. People forget to stop counting once the target floor is reached.

An elevator goes up 5 floors and down 4 floors each cycle. From floor 0, how many cycles to reach floor 12?

7. Net gain is 1 per cycle. After 6 cycles it's at 6, in the 7th it reaches 12 during the upward move.

What is the key idea to solve these puzzles correctly?

Simulating until the goal is reached. You must simulate step by step and stop when the target is reached.

If an elevator gains 4 floors and loses 3 floors per cycle, what is the net gain?

1. 4 − 3 = 1 floor per cycle.

Why is the final cycle different from the previous ones?

The elevator stops mid-cycle. The process stops as soon as the target floor is reached.

If an elevator goes up 6 floors and down 5 floors per cycle, how many cycles to reach floor 20?

15. Net gain is 1. After 14 cycles it's at 14, in the 15th it reaches 20 during the upward move.

Which mistake causes most wrong answers in these problems?

Ignoring the final partial cycle. People count only full cycles and forget the last partial one.

An elevator goes up 10 floors and down 8 floors each cycle. From floor 0, when does it first reach floor 18?

After 8 cycles. After 6 cycles it's at 12, in the 7th it reaches 20 during the upward move, so it reaches 18 during cycle 7.

What does this class of puzzles mainly test?

Attention to stopping conditions. They test whether you stop the process at the right moment.

If net gain per cycle is positive, what is guaranteed?

It will eventually reach any finite floor. Any positive net progress eventually reaches a finite target.

If the elevator goes up 3 floors and down 3 floors, what happens?

It never reaches higher floors. Net gain is zero, so it never progresses upward.

Why is using average movement per cycle risky?

The last cycle is incomplete. The final cycle ends before the backward move happens.

If an elevator gains 2 floors per cycle and the target is 10 floors, why isn't the answer always 5 cycles?

Because the last cycle is partial. The last cycle may stop before completing the downward move.

An elevator goes up 7 and down 6 each cycle. How many cycles to reach floor 15?

9. After 8 cycles it's at 8, in the 9th it reaches 15 during the upward move.

What happens if the downward movement is larger than the upward movement?

It never reaches the goal. Net progress is negative, so it never reaches higher floors.

What is the safest method to solve skip logic problems?

Step-by-step simulation. Simulation avoids missing the stopping point.

Which real-world system behaves like these puzzles?

Escalators with setbacks. Any progress-with-setback system follows this pattern.

If an elevator gains 5 and loses 2 each cycle, how many cycles to reach 23?

7. After 5 cycles it's at 15, in the 6th it reaches 20, in the 7th it reaches 25 so it passes 23 during cycle 7.

Why do these puzzles look simpler than they are?

They hide the stopping point. The trick is noticing when to stop counting.

If the target floor keeps increasing faster than the elevator's net gain, what happens?

It never reaches it. If the target moves faster, it can never be caught.

Which is more important: the upward move or the net gain?

Net gain. Only the net gain determines long-term progress.

What happens if net gain is exactly zero?

It never reaches the goal. Zero net gain means no long-term progress.

What is the easiest way to avoid mistakes in these puzzles?

Simulate each step. Step-by-step simulation makes the stopping point obvious.

What is the main lesson of Elevator Skip Logic puzzles?

Stopping conditions matter more than averages. You must always check when the process actually stops.

QuizKnowledge

Elevator Skip Logic: The 12-Floor Challenge

Test your logic skills with this quiz based on the 12-floor elevator pattern challenge, involving unique skips and sequential travel.

25 Questions•20 Mins•Hard