Question

A student wants to create an Android Application to help a motorist to approximate the cost of a journey

by road. The app should enable the user to enter the length of the journey in Kilometres, the amount fuel

that the vehicle uses per kilometre and the cost of fuel per litre. The app should then calculate the total

amount that will be spent on fuel for the journey.

Sketch the interface for the activity that can be used for this task. (5 marks)

b) Declare and initialize all the widgets (views) that you can use for this task. Assume your own ids.

(5 marks)

c) Write the program to calculate the cost of the journey.

Answer 1

Explanation: How to calculate fuel economy and usage

Manufacturers give a fuel economy figure for new cars in litres per 100km for urban, extra urban (i.e. higher speeds) and combined (a mixture of the two). This number is determined via a standardised test which, unfortunately, bears very little resemblance to the type of driving the vast majority of people do. If a vehicle you are looking at purchasing has an indicated fuel economy of 8l/100km, everyday driving is probably more likely to be around 10l/100km (this is my experience, after driving and reviewing over 400 cars since 2007).

However, the manufacturer-supplied figures are good for comparing between models, just not calculating what your expected fuel costs will be.