Question

if two digit number are formed using the digit 1 2 3 4 without repeating them then find n (s)​

Answer 1

We can use permutation here

n = 4

nPr = 4P2

= 4! / 2!

= 4 ×3 × 2 / 2

= 12

12, 21

23,32

34,43

13,31

24,42

14,41

That's all possible cases.