An n - digit number is a positive integer with exactly n - digits. Nine hundred distinct n - digit numbers are to be formed by using the digit 2, 5 and 7 only. The smallest value of n for which this is possible is
Options:
Answer:
B
Solution:
We must have $3^{n} > 900$ The least n satisfying this is 7 .

Question

An n - digit number is a positive integer with exactly n - digits. Nine hundred distinct n - digit numbers are to be formed by using the digit 2, 5 and 7 only. The smallest value of n for which this is possible is

Options:

Answer:

B

Solution:

We must have $3^{n} > 900$ The least n satisfying this is 7 .

TestHub · Accepted Answer

We must have 3 n > 900 The least n satisfying this is 7 .

Mathematics - Permutation & Combination Question with Solution | TestHub

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