Question

The number of $3-$ digit numbers can be formed from the digits $1,2,3,4$ and $5$ assuming repetition of digits not allowed is

• A. $20$
• B. $30$
• C. $40$
• D. $60$

Answer 1

The correct option is D $60$

Repetition of the digits not allowed is

$1^{st}digit$ $2^{nd}$ digit $3^{rd}$ digit

$1^{st}$ digit 5 ways

$2^{nd}$ digit 4 ways.

$3^{rd}$ digit 3 ways.

No. of 3 digit numbers without repetition = $5\times 4\times 3$

$=20\times 3$

$=60ways$