﻿ Let A be the set of 4-digit numbers a1a2a3a4 where a1 > a2 > a3 > a2 then n (A) is equal to : : Kaysons Education

# Let A be The Set Of 4-digit Numbers A1a2a3a4 where A1 > A2 > A3 > A2 then n (A) Is Equal To :

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## Question

### Solution

Correct option is

210

Select 4 digits out of 10 in 10C4 ways.

As order is fixed for arrangements.          [∴ a1 > a2 > a3 > a4]

Hence No. of ways

= (No. of ways to select ) × 1

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