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How many 4-digit numbers can be formed b...

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

A

3024

B

3000

C

9*9*9

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
A
For the first digit place there are 9 options , second digit place there are 8 options, third digit place there are 7 options and fourth digit place there are 6 options.
so number of 4 digit numbers=`9 xx 8 xx 7xx6=3024`
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