Pavan Putra Boy Pavan Putra Boy - 10 months ago 56
Java Question

Maths query in java

I am not very good in maths . So please don't mind my mistakes !
This is the question :

Speedy kings are a racing group. Their leader John owns a Suzuki
Hayabusa which has a maximum speed of 300 kmph. The leader of the
rival group, Ranson owns a Ducati whose maximum speed is 280 kmph.
John makes n rounds of 10km track. How much time(in minutes) will
Ranson take to complete the same distance covered by John. Take the
value of n as input from the user. Sample Input: 4 Sample Output: 8

Now this is my solution :

class speedyKings{
public static void main(String args[]){
Scanner in=new Scanner(;
int ducs=280;
int hays=300;
int total_dist=10000;
int n=in.nextInt();
double time=((10000*n)/280);

But it is not giving the right output can anybody help ?

Answer Source

Your best bet is to take small steps to get to the right value. You can use appropriately named variables to remember what you're looking at and working with:

Scanner in = new Scanner(;
int laps = in.nextInt();
double speedInKph = 280; // km/h
double lapLength = 10000; // meter
double speedInMpS = speedInKph * 1000 / 3600; // m/s
double secondsPerLap = lapLength / speedInMpS; // m / (m/s) = s
double minutesPerLap = secondsPerLap / 60;
double minutes = minutesPerLap * laps;

System.out.println("Minutes: " + minutes);