Question

A man car covers 12 Km in 5 hours. His speed in m/min is:
$\left( A \right)40$
$\left( B \right)\dfrac{{12}}{5}$
$\left( C \right)\dfrac{{12}}{{60}}$
$\left( D \right)\dfrac{{1200}}{{60}}$

Answer 1

Hint – In this particular question use the concept that first convert the given distance covered by the car and the time taken in meter and minute respectively by using (1 Km = 1000 m and 1 hr. = 60 min) then use the relation of speed, distance and time so use these concepts to reach the solution of the question.

Complete step-by-step answer:
Given data:
A man car covers 12 Km in 5 hours.
So the distance car covers = 12 Km.
As we know 1 Km = 1000 m.
So 12 Km in meters is the product of the number of Km’s and the meters in 1 Km.
So 12 Km = 12 (1000) = 12000 m.
Let the distance be denoted by S.
Therefore, S = 12000 m.
Now he covers this distance in 5 hours.
Let the time taken be denoted by t.
Therefore, t = 5 hours.
Now as we know that 1 hours = 60 minutes.
So 5 hours in minutes is the product of the number of hours and the minutes in 1 hours.
Therefore, 5 hours = 5 (60) = 300 minutes.
Now as we the relation between the distance, speed and time is given as,
Speed of the car is the ratio of the distance covered by the car and the time taken by the car.
Let the speed of the car be v m/min.
So the speed of the car is
$ \Rightarrow v = \dfrac{S}{t}$ m/min.
Now substitute the values we have,
$ \Rightarrow v = \dfrac{{12000}}{{300}}$ m/min.
Now simplify this we have,
$ \Rightarrow v = \dfrac{{120}}{3} = 40$ m/min.
So this is the required answer.
Hence option (A) is the correct answer.

Note –Whenever we face such types of question the key concept we have to remember is that the relation between the speed, distance and time which is given as, distance covered by any object is the product of the speed of the object and the time taken by the object, then convert the units of these according to the asked units as above we will get the required speed of the car in m/min.