We are told:
• Anton, Beatrice, and Carl each run at constant rates.
• The race is 30 km long.
• Anton’s time + Beatrice’s time = Carl’s time + 3 hours
• Question: Did Carl win the race? → i.e., Was Carl’s time less than both Anton’s and Beatrice’s?
Let’s denote:
• Let T_A, T_B, T_C be the time each of them took to finish.
• Given: T_A + T_B = T_C + 3
So the question becomes: Is T_C < T_A and T_C < T_B?
⸻
Statement (1):
None of the three ran faster than 6 km/hr.
That is:
• Each person’s speed ≤ 6 km/hr
• So, their time ≥ \frac{30}{6} = 5 hours
→ So all times are at least 5 hours.
This gives us a lower bound, but no specific relationship between their individual times.
Let’s explore with an example:
• Suppose:
• Anton took 6 hrs → T_A = 6
• Beatrice took 6 hrs → T_B = 6
• Then T_C = T_A + T_B - 3 = 6 + 6 - 3 = 9
→ Carl took 9 hours, which is more than both → Carl did NOT win
Try another example:
• Anton = 5.5 hrs, Beatrice = 5.5 hrs → T_C = 11 - 3 = 8
→ Carl still loses
What if:
• Anton = 5 hrs, Beatrice = 5 hrs → T_C = 7 → Carl still loses
Conclusion: Carl could have taken more than Anton and Beatrice, depending on their times, while staying under 6 km/hr.
So:
✅ Statement (1) is NOT sufficient
⸻
Statement (2):
Anton finished before Beatrice
→ T_A < T_B
We still have T_A + T_B = T_C + 3
Let’s test possibilities:
Say:
• T_A = 5, T_B = 6 → total = 11 → T_C = 8
Now:
• Carl = 8, Anton = 5, Beatrice = 6 → Carl loses to Anton
Try:
• T_A = 5.9, T_B = 6 → T_C = 8.9 → Carl loses
Try:
• T_A = 6, T_B = 6 → T_C = 9
→ Seems like Carl’s time is always more than both
BUT try flipping it:
What if:
• T_A = 1, T_B = 11 → T_C = 9
→ Anton finishes in 1 hour → Carl 9 hours → Carl loses
BUT reverse:
Try T_A = 6, T_B = 6.5 → then T_C = 9.5
→ Anton < Beatrice, but Carl is still slower
So it seems like Carl is always slower.
But we can’t guarantee that Carl is slower than both, only that the sum of two is 3 more than Carl. What if Anton took 10, Beatrice took 5 → total 15, so Carl = 12
Then:
• Carl = 12
• Anton = 10
• Beatrice = 5 → Carl beats Beatrice
So Carl did not beat both → so did not win
But what if Anton = 8, Beatrice = 7 → Carl = 12 → Anton faster
So again, Carl doesn’t win
But is it always the case? Can Carl ever win?
Try Anton = 7, Beatrice = 6 → sum = 13 → Carl = 10
Then: Carl < both? No. Carl < 6? No.
Let’s suppose Carl = 5. Then T_A + T_B = 8
But with T_A < T_B, pick T_A = 3.5, T_B = 4.5 → Carl = 5
Carl > both → Carl did not win
But if we try T_A = 2, T_B = 6 → Carl = 5
Carl faster than Beatrice, slower than Anton → did not win
But what if T_A = 2, T_B = 5.5 → Carl = 4.5 → Carl wins
→ But then T_C = 4.5, which is less than Anton’s time 2 → impossible.
Oops! Contradiction.
But in this case Carl < both → Carl wins.
So Carl can win depending on time combinations.
Hence:
❌ Statement (2) alone is NOT sufficient
⸻
Now combine (1) and (2):
From (1): all speeds ≤ 6 km/hr → times ≥ 5 hours
From (2): T_A < T_B
Try values:
• Anton = 5, Beatrice = 5.1 → sum = 10.1 → Carl = 7.1
→ Carl > Anton → loses
Try Anton = 5.9, Beatrice = 6 → sum = 11.9 → Carl = 8.9 → Carl loses
Try Anton = 5.5, Beatrice = 5.6 → Carl = 8.1 → Carl still loses
Try:
• Anton = 5, Beatrice = 8 → sum = 13 → Carl = 10 → Carl > Anton → loses
So under constraints of both:
• Everyone’s time ≥ 5
• Anton < Beatrice
Then:
T_C = T_A + T_B - 3 > T_A
\Rightarrow T_C > T_A
Also:
T_C = T_A + T_B - 3 < T_B \quad ?
\Rightarrow T_A + T_B - 3 < T_B \Rightarrow T_A < 3
But if T_A < 3, and from (1), time must be ≥ 5 → contradiction.
So:
T_C < T_B \Rightarrow T_A < 3 \Rightarrow \text{Not possible under (1)}
\Rightarrow T_C > T_B
Hence:
T_C > T_A \text{ and } T_C > T_B \Rightarrow \text{Carl took longer than both} \Rightarrow \boxed{\text{Carl did NOT win}}
✅ Together (1) and (2) are sufficient
⸻
✅ Final Answer: C. Both statements together are sufficient