Answer : 1. "9!/(2!)^{2}x3!"
Explanation :

Answer: A) 9!/(2!)^{2}x3! Explanation: n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.The letter pattern 'MESMERISE' consists of 10 letters of which there are 2M's, 3E's, 2S's and 1I and 1R.Number of arrangements = 9!(2!)2×3!