# Print all pairs of two digit twin prime numbers using for loop in C

###### for Loop - Question 11

In this question, we will see how to print all pairs of two-digit twin-prime numbers in C programming using for loop. To know more about for loop click on the for loop lesson.

Q11) Write a program in C to print all pairs of two-digit twin-prime numbers using for loop.

A twin-prime numbers are numbers that differs from another prime number by two. Examples of two-digit twin-prime numbers are: (11, 13), (17, 19), (29, 31), (41, 43), etc.

#### Program

``````#include <stdio.h>
#include <conio.h>

int main()
{
int i,j,fc,n;
printf("List of all twin prime numbers between 10 to 99\n");
for(i=10; i<=99; i=i+1)
{
fc=0;
for(j=1; j<=i; j=j+1)
{
if(i%j==0)
{
fc=fc+1;		// counting the factors of i (value of i)
}
}

if(fc==2)
{
fc=0;
n=i+2;		// taking another number from the current value of i with a difference of 2

for(j=1; j<=n; j=j+1)
{
if(n%j==0)
{
fc=fc+1;		// counting the factors of n (value of n)
}
}

if(fc==2)
{
printf("(%d, %d)\n",i,n);
}
}
}
return 0;
}``````

#### Output

```List of all twin prime numbers between 10 to 99
(11, 13)
(17, 19)
(29, 31)
(41, 43)
(59, 61)
(71, 73)```