Question

A briefcase has a three- digit lock code that doesn't include zero as a digit. What is the probability that the lock code consists of all even digits if the same digit is not used more than once.

Answer 1

Answer:

1/21.

Step-by-step explanation:

There are 9 digits and the total number of permutations of 3 from 9 is 9P3

= 9!/6!  = 504.

There are 4 even digits so the number of permutations of 3 from these 4 is 4!  (4-3)!  = 4*3*2 = 24.

So the required probability =  24/504

= 1/21.