Bunuel wrote:
FRESH GMAT CLUB QUESTION:
A fair six-sided dice was rolled n times. What is the value of n?
(1) The number of different possible sequences of n-digit numbers when a dice is rolled n times is 7776.
(2) If the dice has been rolled 3 times fewer, the probability of getting a 6 on every roll would have been 1/36.
Total outcome when a fair dice is rolled n times = 6^n
(1) Given 6^n = 7776 = 6^5
—> n = 5
Sufficient
(2) Probability of getting 6 on every roll of(n-3) is 1/6^(n - 3) = 1/36
—>
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