Question

A combination lock like the one shown below has three

dials. Each of the dials has numbers ranging from 1 to 25. If
repeated numbers are allowed, how many different
combinations are possible with the lock?​

Answer 1

15625

Explanation:

Let us consider each dial individually.

We have 25 choices for the first dial.

We then have 25 choices for the second dial.

We then have 25 choices for the third dial.

Let us consider any particular combination, the probability that combination is right is (probability the first number is right) * (probability the second number is right) * (probability the third number is right) = 1/25 * 1/25 * 1/25 = 1/15625

Therefore there are 15625 combinations