We can use the formula:
distance = speed x time
to solve the problem.
We are given that the train covers 36 km in 21 minutes. We want to find how long it will take to cover 60 km.
Let's first convert 21 minutes to hours:
21 minutes = 21/60 hours = 0.35 hours
Now we can use the formula to find the speed of the train:
36 km = speed x 0.35 hours
Solving for speed, we get:
speed = 36/0.35 km/h
Using a calculator, we can evaluate this expression to get:
speed = 102.86 km/h
Now we can use the speed to find the time it takes to cover 60 km:
60 km = 102.86 km/h x time
Solving for time, we get:
time = 60/102.86 hours
Converting this to minutes, we get:
time = (60/102.86) x 60 minutes
Simplifying this expression, we get:
time = 35 minutes (approx)
Therefore, the train will take approximately 35 minutes to cover 60 km.
So the correct option is 1.