Let the mean and variance of 12 observations be 9/2 and 4 respectively. Later on, it was observed that two observations were considered as 9 and 10 instead of 7 and 14 respectively. If the correct variance is m/n, where m and n are coprime, then m + n is equal to
(1) 316
(2) 317
(3) 315
(4) 314
