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Let A be the set of 4- digit numbers a1a...

Let A be the set of 4- digit numbers `a_1a_2a_3a_4` where `a_1gt a_2 gt a_3 gt a_4` then n(A) is equal to

A

126

B

84

C

210

D

None of these

Text Solution

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The correct Answer is:
C
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