NDA 2024 · PYQ · Probability / Permutations · medium
If the letters of the word "TIRUPATI" are written down at random, then what is the probability that both Ts are always consecutive?
A.1/2
B.1/4✓ Correct
C.1/7
D.1/14
Explanation
TIRUPATI has 8 letters with T appearing twice and I appearing twice. Total arrangements = 8!/(2!·2!) = 10080. Treating both Ts as one unit, we have 7 items (TT, I, R, U, P, A, I) with I repeated twice. Arrangements = 7!/2! = 2520. Probability = 2520/10080 = 1/4.
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