Question
Rogelio's watch stopped at 2:00 p.m. He started it without changing the time and went to visit a friend. When he arrived, he was told that it was 4:10 p.m. He stayed with his friend for exactly two hours and walked back home, taking the same amount of time as he had left. He went to the clock, which at that moment read 4:40 p.m., and set it to the correct time. How could he have known? Rogelio, what was the exact time? What was the exact time?
142
likes712 views
Answer to a math question Rogelio's watch stopped at 2:00 p.m. He started it without changing the time and went to visit a friend. When he arrived, he was told that it was 4:10 p.m. He stayed with his friend for exactly two hours and walked back home, taking the same amount of time as he had left. He went to the clock, which at that moment read 4:40 p.m., and set it to the correct time. How could he have known? Rogelio, what was the exact time? What was the exact time?
Neal
4.5105 Answers
1. Let \( t \) be the time taken to walk from Rogelio's home to his friend's house.
2. Rogelio's journey: \( \text{Left home at 2:00 p.m.} \)
3. Rogelio's friend told him the correct time was 4:10 p.m. after arriving.
2:00 \, \text{p.m.} + t = 4:10 \, \text{p.m.}
4. Determine \( t \):
t = 4:10 \, \text{p.m.} - 2:00 \, \text{p.m.}
t = 2 \, \text{h} \, 10 \, \text{min}
5. Rogelio stayed for 2 hours:
\text{Leave friend's house at 4:10 p.m.} + 2 \, \text{h} = 6:10 \, \text{p.m.}
6. Walk home taking \( t \) time:
6:10 \, \text{p.m.} + 2 \, \text{h} \, 10 \, \text{min} = 8:20 \, \text{p.m.}
7. On arriving, Rogelio's watch reads 4:40 p.m. but needs setting to correct time:
\text{Current time display} + (\text{correct time difference})
4:40 \, \text{p.m.} + 10 \, \text{min} = 4:50 \, \text{p.m.}
8. Exact time is:
5:10 \, \text{p.m.}
2. Rogelio's journey: \( \text{Left home at 2:00 p.m.} \)
3. Rogelio's friend told him the correct time was 4:10 p.m. after arriving.
4. Determine \( t \):
5. Rogelio stayed for 2 hours:
6. Walk home taking \( t \) time:
7. On arriving, Rogelio's watch reads 4:40 p.m. but needs setting to correct time:
8. Exact time is:
Frequently asked questions (FAQs)
What is the variance of the dataset {5, 7, 9, 10, 12}?
+
Find the derivative of f(x) = sin(x)cos(2x) + cos(x)sin(2x) - tan(x)sec^2(x).
+
Question: If the sum of two numbers is 15 and their product is 36, what are the two numbers?
+
New questions in Mathematics