Question

A password for a computer uses three distinct digits from 0 to 9. What is the probability that the password solely consists of prime numbers or zero

Answer 1

5c3/10c3

I hope it helps

Answer 2

• Prime numbers from 1-9 are 2,3,5,7.
• So the password should consist of either three out of 0,2,3,5,7.
• Total number of possible combinations=¹⁰C₃.

• Number of possible combinations with prime numbers=⁵C₃.

∴Probability that password consists of prime numbers=

(Number of possible combinations with prime numbers)/(

Total number of possible combinations)

=⁵C₃/¹⁰C₃

=1/12