Why is IST ahead of GMT ?????

EVERY COUNTRY HAS A STANDARD LONGITUDE.OUR COUNTRY'S STANDARD LONGITUDE IS 82 1/2 DEGREES OR 82 DEGREES 30 MINUTES (1 DEGREE = 60 MINUTES). IST IS AHEAD OF GMT BECAUSE WE ARE 82 1/2 DEGREES AHEAD OR ON THE EAST SIDE OF IT. AND WE ARE 5:30 MINUTES AHEAD. THIS IS BCS EARTH TURN 360 DEGREESS IN 24 HOURS SO 15 DEGREES IN 1 HOUR AND 1 DEGREES IN 4 MINUTE SO INDIA'S STANDARD LONGITUDE IS 82 1/2 DEGREES SO WE TO FIND THE STANDARD TIME WE HAVE TO MULTIPLY STANDARD LONGITUDE TO EAST OR WEST BY 4. SO 82 1/2 DEGREES X 4 = 330 MINUTES WHICH IS EQUAL TO 5 HOURS AND 30 MINUTES.