If ${}^{n}C_x=56$ and ${}^{n}P_x=336$, then $n$ is equal to

Important Questions on Permutations and Combinations

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IMPORTANT

Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 2

How many numbers greater than $50000$ can be formed with digits $4,5,6,7$ and $8$ if no digit being repeated?

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 3

In how many ways can $10$ soldiers stand in two rows having $5$ soldiers in each row?

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 4

If the maximum number of trials required to open all locks when there are $n$ locks and $n$ keys is $105$, then $n$ equals

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 6

How many different words can be made with the letters of the word NAINITAL such that each of the word begins with $L$ and ends with $T$?

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 7

How many numbers greater than a million can be formed with the digits $5,5,2,2,1,7,6$?

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 8

How many different signals can be given using any number of flags from $5$ flags of different colours?

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 9

The number of permutations of $n$ different objects taken $k$ at a time, when repetitions are allowed is

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Gamma Question Bank for Engineering Mathematics>Chapter 7 - Permutations and Combinations>Assignment>Q 10

Number of natural numbers not exceeding $4321$ can be formed with the digits $1,2,3,4$ if repetition is allowed is