**fig2_12.txt**

/* 1*/	void
/* 2*/	Pair( const unsigned int N )
/* 3*/	{
/* 4*/	    int Rel = 0, Tot = 0;

/* 5*/	    for( int i = 1; i <= N; i++ )
/* 6*/	        for( int j = i + 1; j <= N; j++ )
/* 7*/	        {
/* 8*/	            Tot++;
/* 9*/	            if( Gcd( i, j ) == 1 )
/*10*/	                Rel++;
/*11*/	        }

/*12*/	    cout << "Fraction of relatively prime pairs is  "
/*13*/	        << double( Rel ) / double( Tot ) << endl;
/*14*/	}