Question

if no digit may be used more then once,how many 2 digit numbers can be formed using only the digits 5 6 3 2.
11
12
10
2

Answer 1

actually, it is 4P2
use the formula :
nPr = n!/(n-r)!

Answer 2

?

Answer 3

10

Answer 4

5, 6, 3, 2

Answer 5

count them, we have 4 digits to fill in 2 spaces, eh ?