JEE Main · MathematicsEasy

$How many different 3-digit numbers can be formed using the digits $1, 2, 3, 4,$ and 5 if repetition of digits is not allowed?$

Show correct answer & step-by-step solution

Correct answer: A — $60$

Solution

$W e n ee d t o f or ma 3 - d i g i t n u mb er u s in g t h ese t o f 5 d i g i t s 1, 2, 3, 4, 5 w i t h o u t r e p e t i t i o n .$
$The number of ways to choose and arrange 3 digits from 5 is given by the permutation formula P (5, 3) = 5 \times 4 \times 3 .$
$Calculating the product, we find 5 \times 4 \times 3 = 60 .$
$Hence the answer is (A).$