Kibet left school by bicycle at 8:00 a.m. and took 1 ½ hours to reach the market 20 km away. Akinyi left the school for the market by car at 8:30 a.m. The average speed of the car was 80 km /h. What was the difference between their arrival times?
Ta = 8:00AM + 1 1/2h = 9:30 AM. = Time
arrived.
d = r*T = 20 km
T = 20/r = 20/80 = 1/4 h. = 15 min. Travel time.
Ta = 8:30AM + 15 min = 8:45 AM. = Time
arrived.
9:30AM - 8:45AM = 8:90 - 8:45 = :45 Min
= Difference in arrival time.
To find the difference between their arrival times, we need to calculate the time taken by each person to reach the market.
Kibet took 1 ½ hours = 1.5 hours to travel a distance of 20 km. We can use the formula: Speed = Distance / Time to find Kibet's speed.
Speed = Distance / Time
Speed = 20 km / 1.5 hours = 13.33 km/h
Now, we calculate the time it took for Akinyi to reach the market. He left school at 8:30 a.m. and traveled at an average speed of 80 km/h. The distance is the same as Kibet's, which is 20 km. Again, we can use the formula: Time = Distance / Speed.
Time = Distance / Speed
Time = 20 km / 80 km/h = 0.25 hours
To convert 0.25 hours to minutes, we multiply by 60:
0.25 hours * 60 minutes/hour = 15 minutes
So, Akinyi took 0.25 hours = 15 minutes to reach the market.
To find the difference between their arrival times, we subtract the time taken by Kibet from the time taken by Akinyi:
Difference = Akinyi's time - Kibet's time
Difference = 15 minutes - 1.5 hours (converted to minutes)
To subtract 1.5 hours from 15 minutes, we need to convert 1.5 hours to minutes:
1.5 hours * 60 minutes/hour = 90 minutes
Difference = 15 minutes - 90 minutes
Difference = -75 minutes
The negative sign indicates that Kibet arrived earlier than Akinyi. Therefore, the difference in their arrival times is 75 minutes, with Kibet arriving 75 minutes earlier.