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

likes
712 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?

Expert avatar
Neal
4.5
105 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.}

Frequently asked questions (FAQs)
What are the key characteristics of the ellipse function given by (x-h)^2/a^2 + (y-k)^2/b^2 = 1?
+
What is the derivative of y = 3x^2 + 2x - 4?
+
What are the equation's characteristics for a hyperbola represented by (x^2/a^2) - (y^2/b^2) = 1 ?
+
New questions in Mathematics
A particular employee arrives at work sometime between 8:00 a.m. and 8:50 a.m. Based on past experience the company has determined that the employee is equally likely to arrive at any time between 8:00 a.m. and 8:50 a.m. Find the probability that the employee will arrive between 8:05 a.m. and 8:40 a.m. Round your answer to four decimal places, if necessary.
a runner wants to build endurance by running 9 mph for 20 min. How far will the runner travel in that time period?
A circle with a 12-inch diameter is folded in half and then folded in half again. What is the area of the resulting shape?
Imagine that you are in an electronics store and you want to calculate the final price of a product after applying a discount. The product you are interested in has an original price of $1000 MN, but, for today, the store offers a 25% discount on all its products. Develop an algorithm that allows you to calculate the final price you will pay, but first point out the elements.
A drawer contains three pairs of white socks, five pairs of black socks and two pairs of red socks. Caden randomly selects two pairs of socks on his way to the gym. What is the probability that both pairs of socks are black?
In a store there are packets of chocolate, strawberry, tutti-frutti, lemon, grape and banana sweets. If a person needs to choose 4 flavors of candy from those available, how many ways can they make that choice?
Clara usually walks briskly to the farmers' market and it takes her 22 minutes. Today she walked leisurely and it took 61/2 minutes. How much more time than usual did she take to reach the market today?
If 0101, what is the binary representation of the 4x16 decoder output?
Prove that it is not possible to arrange the integers 1 to 240 in a table with 15 rows and 16 columns in such a way that the sum of the numbers in each of the columns is the same.
The Humane Society has asked for our help again this week. Currently they are charging $50 for an adoption fee. Unfortunately they just pulled this number out of the air and do not know why they are charging this amount. They would like to charge an amount that covers all the adoption costs – both the variable costs for adoptions as well as the fixed cost for the kennel portion of the Humane Shelter operations. We can help them by doing a breakeven analysis. During a client meeting we gathered these facts. There are 2 part-time employees that each earn $1000 per month. The utilities for the kennel area (water, electricity) are $200 per month. The average food cost for animals in the kennel is $800 per month. In addition, each animal that is adopted receives a rabies vaccination that costs $4 and is micro-chipped that costs $6. At the current cost of $50, how many animals must be adopted to break-even? What would break-even be at a $60 adoption fee? What would break-even be if the fee were lowered to $40? The newspaper has suggested that the Humane Society advertise to increase pet adoptions. The package that they have recommended costs $1000 for a very small ad run every day for a month. If the Humane Society does this extra advertising, how will it affect breakeven? Based on what you have learned about elasticity, what price do you recommend for the adoption fee?
If X1 and X2 are independent standard normal variables, find P(X1^2 + X2^2 > 2.41)
Use linear approximation to estimate the value of the sine of 31o.
Find the minimum value of the function y = -4 x3 + 60 x2 -252 x + 8 for values of x between x = 0 and x = 9 Enter the value of the function, not the value of x
16.What payment (deposit) made at the end of each month will accumulate to $10473 in 13 years at 7.9% compounded monthly? Enter to the nearest cent (two decimals). Do not use $ signs or commas in the answer.
Find the equation of a straight line that has slope 3 and passes through the point of (1, 7) . Write the equation of the line in general forms
How do you convert a fraction to a decimal
Write the inequality in the form of a<x<b. |x| < c^2
P 13. Let P a point inside of a square ABCD. Show that the perpendicular lines drawn from A, B, C, respectively D, to BP, CP, DP, respectively AP are concurrent. Use geometric rotation.
A group of 17 people spent 9 days on vacation and spent R$776.34 on barbecue meat and the bill needs to be divided as follows: 6 people stayed for 9 days, 7 people stayed for 4 days, and 2 people stayed for 5 days and 2 people stayed 3 days, how much does each group have to pay for the days they stayed?
y’’ -4y’ +4y = (12x^2 -6x)e^2x Y(0)= 1 Y’(0)=0 Y(x)=c1y1+c2y2+yp