Analysing a problem - how long a train?

Analysing a Programming Task example from a Well House Consultants training course
More on Analysing a Programming Task [link]

This example is described in the following article(s):
• Specification, Design, Implementation, Testing and Documentation - stages of a (Java) programming project - [link]

Source code: Trainlength.java Module: Q904

public class Trainlength {

/* Problem ... you have "x" people to transport home from a day out
in Weymouth by train. The train is from 1 to 5 carriages in length,
and you're asked to provide 5 seats for every 4 people if you can.
Each carriage can seat 75 people. */

/* Method - start with 1 carriage and work out the loading ... if it's
greater that 4/5 (0.8) add another carriage and work out the loading
again. Keep going until you have plenty of seats, or until you've
got 5 carriages so can't run any longer (short platform, Freshford). */

/* It's part of the programmers skills to pick out the irrelevant (the
fact that Freshford is a problem) from the relevant ;-) */

public static void main (String[] args) {

// Initial stuff

int cars = 0;
int passengers = 250;
int ppc = 75;
float loading = 99.0f;

// Stuff which you do for each possible length

while (cars < 5 && loading > 0.8f) {
        cars += 1;
        loading = (float)passengers / (float)(ppc * cars);
        System.out.println("With "+cars+" cars, loading is "+loading);
        }

// Stuff you do once at the end

System.out.println("Have a great day in Weymouth");

}

}

/* Running that program ...

munchkin:jj11 grahamellis$ java Trainlength
With 1 cars, loading is 3.3333333
With 2 cars, loading is 1.6666666
With 3 cars, loading is 1.1111112
With 4 cars, loading is 0.8333333
With 5 cars, loading is 0.6666667
Have a great day in Weymouth
munchkin:jj11 grahamellis$

*/

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