# Program to find the number of men initially

• Last Updated : 15 Apr, 2021

A certain number of men can do a certain piece of work in D days. If there were m more men engaged in the work then the work can be done in d days less. The task is to find how many men were there initially.
Examples:

Input: D = 5, m = 4, d = 4
Output: 1
Input: D = 180, m = 30, d = 20
Output: 240

Approach: Let the initial number of men be M and days be D
Amount of work completed M men in D days will be M * D
i.e. Work Done = M * D …(1)
If there are M + m men then the same amount of work is completed in D – d days.
i.e. Work Done = (M + m) * (D – d) …(2)
Equating equations 1 and 2,

M * D = (M + m) * (D – d)
M * D = M * (D – d) + m * (D – d)
M * D – M * (D – d) = m * (D – d)
M * (D – (D – d)) = m * (D – d)
M = m * (D – d) / d

Below is the implementation of the above approach:

## C++

 // C++ implementation of above approach. #include using namespace std;   // Function to return the // number of men initially int numberOfMen(int D, int m, int d) {       int Men = (m * (D - d)) / d;       return Men; }   // Driver code int main() {     int D = 5, m = 4, d = 4;       cout << numberOfMen(D, m, d);       return 0; }

## Java

 // Java implementation of the approach import java.util.*;   class GFG {       // Function to return the // number of men initially static int numberOfMen(int D, int m, int d) {       int Men = (m * (D - d)) / d;       return Men; }   // Driver code public static void main(String args[]) {     int D = 5, m = 4, d = 4;       System.out.println(numberOfMen(D, m, d));   } } // This code is contributed by Arnab Kundu

## Python3

 # Python implementation of above approach.   # Function to return the # number of men initially def numberOfMen(D, m, d):     Men = (m * (D - d)) / d;       return int(Men);     # Driver code D = 5; m = 4; d = 4;   print(numberOfMen(D, m, d));     # This code contributed by Rajput-Ji

## C#

 //  C# implementation of the approach using System;   class GFG {       // Function to return the // number of men initially static int numberOfMen(int D, int m, int d) {       int Men = (m * (D - d)) / d;       return Men; }   // Driver code public static void Main() {     int D = 5, m = 4, d = 4;       Console.WriteLine(numberOfMen(D, m, d));   } }   // This code is contributed by anuj_67..

## Javascript



Output:

1

My Personal Notes arrow_drop_up
Recommended Articles
Page :