Question

A combination lock has numbers 0-49 on it. How many different 3-digit lock

combinations are possible if no digit can be repeated?

Answer 1

19,600

Explanation:

0-49=50 numbers

n=50

r=3

C(n,r)=n!/(r!(n-r)!)

=50!/(47!)(3!)

C(n,r)=C(50,3)

=50!/(3!(50−3)!)

= 19600