1) at 65kph,mrs Escarcha can reach home within 50 mins.at what rate should she drive her car so that he can reach home 10 minutes earlier?
2) Five people can finish painting a wall within 5 hours. if only 3 people are available, how many hours do they have to work to finish the same job?
distance = 65(50/60) = 325/6 km
rate needed to have a time of 40 minute
= (325/6) / (40/50
= (325/6)(5/4) = 1625/24 km/h or appr 67.7 km/h
#2
job needs 25 man-hours to complete.
so if 3 men work, number of hours
= 25/3 hrs, or 8 hours and 20 minutes
1) To solve this problem, let's first convert the given time into hours. We are given that Mrs. Escarcha can reach home within 50 minutes at a speed of 65 kph.
Step 1: Convert 50 minutes to hours.
50 minutes ÷ 60 minutes/hour = 0.83 hours
Step 2: Now that we have the time in hours, we can calculate the distance covered in 50 minutes at a speed of 65 kph.
Distance = Speed × Time
Distance = 65 kph × 0.83 hours
Distance = 53.95 km
Step 3: For Mrs. Escarcha to reach home 10 minutes earlier than her usual time, we need to reduce her travel time by 10 minutes.
Reduced time = 50 minutes - 10 minutes = 40 minutes
Step 4: Now, we need to find the speed at which Mrs. Escarcha should drive her car to cover the reduced distance in 40 minutes.
Speed = Distance ÷ Time
Speed = 53.95 km ÷ (40 minutes ÷ 60 minutes/hour)
Speed = 80.93 kph
Therefore, Mrs. Escarcha should drive her car at a speed of approximately 80.93 kph to reach home 10 minutes earlier.
2) In this problem, we are given that five people can finish painting a wall within 5 hours. Now we need to find out how many hours it would take for only three people to finish the same job.
Step 1: Let's assume that the wall is the same size and requires the same amount of work to be completed, regardless of the number of people involved. This assumption allows us to use the concept of person-hours.
Step 2: Calculate the total person-hours required to complete the job by five people in 5 hours.
Total person-hours = Number of people × Number of hours
Total person-hours = 5 people × 5 hours
Total person-hours = 25 person-hours
Step 3: Now, let's calculate how many person-hours it would take for three people to finish the same job.
Person-hours for three people = Total person-hours ÷ Number of people
Person-hours for three people = 25 person-hours ÷ 3 people
Person-hours for three people = 8.33 person-hours
Step 4: Since it is not possible to work in partial person-hours, we need to round up the value to the next whole number. Hence, three people would have to work for 9 hours to complete the same job.
Therefore, if only three people are available, they would have to work for 9 hours to finish the painting job.