Question

The second class railway fare for 240 km of journey is Rs 15.00. What would be the fare for a journey of 139.2 km? Assume that the fire varies directly as the length of the journey.

Answer 1

Hint: To solve this problem we are going to use the unitary method. In the unitary method you find the value of a unit and then the value of a required number of units. Here, we first calculate the fair per km then we can calculate the fair for 139.2 km by multiplying it by the fair per km.

Complete step-by-step answer:
Given: Fare of 240 km journey = Rs. 15.00
Using the unitary method. We first calculate the fare per km,
Fare of 1 km journey = $\dfrac{{Rs.15.00}}{{240km}}$
As we have to find a fare for 139.2 km.
As given, fare varies directly as the length of the journey.
So, we will multiply the fare per km with the total distance,
So fare for 139.2 km journey = $\dfrac{{Rs.15.00}}{{240km}} \times 139.2km = Rs.8.7$
Hence, the fare of a journey of 139.2 km is Rs.8.7 .
So, the correct answer is “Rs.8.7 ”.

Note: The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value. In essence, this method is used to find the value of a unit from the value of a multiple, and hence the value of a multiple. When we are solving the problem we should keep in mind that we have to find fare per km. Maybe some of you calculate the km per rupee, then you are not able to calculate the total fare price for 139.2 km. So, always do calculations with attention. keep in mind what our desired output is.