Question

permutations and combination question

How many arrangements of four digit numbers can be made using the numbers 2 through 9 if no numbers can be repeated?

a) 840

b) 504

c) 1680

d) 4096

Answer 1

Answer:

Step-by-step explanation:

2,3,4,5,6,7,8,9 = 8 números diferentes

$\frac{8!}{4!} = 8.7.6.5 = 56 *30 = 1680$