Explanation:
To find the time it would take to complete the journey at a decreased speed, we can use the formula:
Time = Distance / Speed
Given that the cyclist completes the journey in 40 minutes at a speed of 15 km/hr, we need to convert the time to hours:
40 minutes = 40/60 = 2/3 hours
Let's calculate the distance traveled by the cyclist using the formula:
Distance = Speed * Time
Distance = 15 km/hr * 2/3 hours
Distance = 10 km
Now, we can find the time it would take to complete the same journey at a speed of 12 km/hr:
Time = Distance / Speed
Time = 10 km / 12 km/hr
Calculating the time:
Time = 5/6 hours
To convert the time back to minutes:
Time = (5/6) * 60 minutes
Time = 50 minutes
Therefore, if the speed is decreased to 12 km/hr, the same journey would take 50 minutes to complete.