Question

function "count_heads()" that takes two inputs N and R. the function should return the probability of getting exactly R heads on N successive tosses of a fair coin. A fair coin has equal probability of loading a head or a tail( i.e 0.5) on each toss​

Answer 1

Answer:

Probability of getting K heads in N coin tosses

Given two integers N and R. The task is to calculate the probability of getting exactly r heads in n successive tosses.

A fair coin has an equal probability of landing a head or a tail on each toss.

Examples:

Input : N = 1, R = 1

Output : 0.500000

Input : N = 4, R = 3

Output : 0.250000

Answer 2

Answer:

Given two integers N and R. The task is to calculate the probability of getting exactly r heads in n successive tosses.

A fair coin has an equal probability of landing a head or a tail on each toss.

include <bits/stdc++.h>  

using namespace std;  

 

// function to calculate factorial  

int fact(int n)  

{  

   int res = 1;  

   for (int i = 2; i <= n; i++)  

       res = res * i;  

   return res;  

}  

 

// apply the formula  

double count_heads(int n, int r)  

{  

   double output;  

   output = fact(n) / (fact(r) * fact(n - r));  

   output = output / (pow(2, n));  

   return output;  

}  

 

// Driver function  

int main()  

{  

   int n = 4, r = 3;  

     

   // call count_heads with n and r  

   cout << count_heads(n, r);  

   return 0;  

}  

Output:

0.250000

hope it help u