Question

The number of five-digit numbers having atleast one of their digits repeated is :

• A. $90000$
• B. $100000$
• C. $30240$
• D. $69760$

Answer 1

Answer: (D)

$69760$

No of numbers with repetition

$=10\times 10\times 10\times 10\times 10$

$\Rightarrow 100000$

No.of numbers without repetition

$=10\times 9\times 8\times 7\times 6$

$\Rightarrow 30240$

No.of numbers with atleast one digit repeated

$=10,0000-30240$

$\Rightarrow 69760$