To determine the time the motorist reached his destination, we need to calculate the total time it took for him to travel both distances.
The time taken to travel the first 40 km at an average speed of 40 km/h can be calculated using the formula:
Time = Distance / Speed
Time = 40 km / 40 km/h = 1 hour
Therefore, the motorist took 1 hour to travel the first 40 km.
The time taken to travel the next 200 km at an average speed of 75 km/h can be calculated in the same way:
Time = Distance / Speed
Time = 200 km / 75 km/h = 2 hours and 40 minutes
Now, we need to add the time taken for both distances to find the total travel time:
Total Travel Time = 1 hour + 2 hours and 40 minutes
To add the time, we convert the 2 hours and 40 minutes into hours. Since there are 60 minutes in an hour, 40 minutes is equal to 40/60 = 2/3 hours.
Total Travel Time = 1 hour + 2 hours and 2/3 hours = 3 and 2/3 hours
Therefore, the motorist took a total of 3 hours and 40 minutes to reach his destination.
If the motorist started his journey at 8:45 am, adding 3 hours and 40 minutes would give us the arrival time:
8:45 am + 3 hours and 40 minutes = 12:25 pm
Hence, the motorist reached his destination at 12:25 pm.