(Speed, Distance and Time)
reaches her school in 10 minutes whereas her friend Dia takes 15 minutes to
reach. This mean Ria takes lesser time than her friend Dia to reach school.
the above, the word ‘time’ has been used. Time is measured in seconds, minutes
When distance and speed are given in the question we measure
time in the following way.
Illustration 1: How much time will be taken to cover a
distance of 100 km at a speed of 10 km per hour?
taken to cover 10 km = 1hr.
taken to cover 1 km = 1/10 hrs.
taken to cover 100km
= 1/10 x 100
Illustration 2: A car covers a distance of 150 km at a
speed of 50 km/hour. Find the time taken to cover this distance.
= 150 km/(50 km/hour)
Illustration 3: A motor cyclist covers a distance of 20
km at a speed of 10km per hour. Calculate the time taken to cover this
= 10 km/hour
covered = 20 km
= 20/10 hour
= 2 hours
Illustration 4: A boy runs at a speed of 20 m per
minute. How much time will be taken to cover a distance of 1km?
m is covered in 1 min
m is covered in 1/20 min
m (i.e. 1km) is covered in 1/20 x 1000 = 50 min