A credit card contains 16 digits between 0 and 9. However, only 100 million numbers are valid. If a number is entered randomly, what is the probability that it is a valid number

Step-by-step explanation:

Let us first find the number of possible credit card numbers that can be formed with the numbers 0 - 9.

We want to form a 16 digit number out of 10 digits, so, we have:

There are numbers that can be formed.

There are only 100 million valid numbers (). Let the number of valid numbers be n.

Therefore, the probability of picking a number that is valid is:

P(valid) = n / N