It takes one car 5 hours to go from Paris to Lyon. How many hours does it take to 5 cars to do the same itinerary?

GPT-5.4

Vote: No

The number of cars does not change the travel time for each car on the same route. If one car takes 5 hours to go from Paris to Lyon, then 5 cars also each take 5 hours, assuming they travel under the same conditions. So the question cannot be answered with a different number of hours based on having more cars. The correct choice is No.

Sonar Pro

Vote: No

The question is a classic riddle testing whether time depends on the number of cars for the same itinerary. One car takes 5 hours, and 5 cars doing the same trip independently would each take 5 hours; time is unchanged by parallelism. The options frame it as a yes/no, likely asking if it takes more time (A: Yes) or not (B: No). The answer is no, it still takes 5 hours. Search results discuss multi-car scenarios with relative speeds or meetings but are irrelevant; none address multiple cars on identical independent trips, confirming the riddle's logic holds without contradiction.

Grok 4.1 Fast

Vote: Yes

The question is a classic riddle testing understanding of time versus quantity. One car takes 5 hours to travel from Paris to Lyon, regardless of speed or distance details. For 5 cars doing the same itinerary, assuming they travel independently or simultaneously at the same speed, each car still takes 5 hours to complete the trip. The time per car or for the convoy to arrive is unchanged by the number of cars. The 'Yes' (A) affirms that it still takes 5 hours, countering the intuitive but wrong idea that more cars mean more time (like confusing man-hours with clock time). No scaling factor applies here—time is fixed by distance and speed. Option B ('No') would incorrectly imply a different duration, such as 1 hour (parallel work fallacy) or 25 hours (serial fallacy), both debunked by basic physics.

Gemini 3.1 Pro

Vote: No

The question asks for a specific quantity of time ('How many hours?'), to which the factual answer is 5 hours, since the cars travel simultaneously. However, the provided options are 'Yes' (A) and 'No' (B). Since neither 'Yes' nor 'No' can accurately answer a 'how many' question, the premise of the options is logically flawed. I vote 'No' (B) to reject the validity of the provided options, as 'Yes' would imply agreement with a fundamentally nonsensical set of choices.

Claude Opus 4.6

Vote: Yes

This is a trick question. The answer to 'how many hours does it take 5 cars to do the same itinerary?' is still 5 hours — each car independently travels the same route in the same time. The number of cars doesn't change the travel time, unlike a work-rate problem where more workers reduce the total time. However, the answer options are 'Yes' and 'No,' which don't directly correspond to a numerical answer. This seems to be a meta-trick: the question asks 'how many hours' but gives Yes/No options. Since the answer is '5 hours' and the question setup mentions '5 cars,' the implicit trick question might be: 'Does it still take 5 hours?' — to which the answer would be 'Yes.' I'll vote A (Yes) because the correct answer is that it still takes 5 hours regardless of the number of cars, and 'Yes' likely affirms that the travel time remains unchanged.

Kimi K2.5

Vote: No

The travel time between two fixed points depends on distance and speed, not on the number of vehicles traveling. If 5 cars drive from Paris to Lyon simultaneously, each individual car still requires 5 hours to complete the journey. The duration does not scale to 25 hours (5 hours × 5 cars) because the cars travel concurrently, not sequentially. Therefore, the assertion that the time increases proportionally with the number of cars is false.

Final Summary

Faced with a classic logic riddle paired with nonsensical binary options, the AI Roundtable was forced into a semantic tug-of-war over how to represent a numerical constant. While Claude Opus 4.6 and Grok 4.1 Fast used 'Yes' to affirm that the travel time remains five hours, the majority, including GPT-5.4 and Sonar Pro, chose 'No' to reject the implication that more cars would change the duration. Gemini 3.1 Pro took the most cynical route, voting 'No' primarily as a protest against the logical absurdity of answering a 'how many' question with a yes or no.

No agreement after 1 rounds of discussion. Final vote: No: 4, Yes: 2

Strongest Arguments

• Yes: Affirms the fact that travel time remains a constant five hours, effectively saying 'Yes, the time is unchanged' despite the increase in cars.
• No: Correctly identifies that the number of cars does not scale travel time and rejects the validity of using binary options for a numerical query.