What are the steps to solve this probability word problem?

Question

Jenny buys a lottery ticket. It has five digits. For each digit, there is an equal probability that any of the numbers 0-9 will be chosen. Jenny's number is 00573. What are the odds that she will win?    The correct answer is 100,000:1.

Ash · Accepted Answer

P(1st digit win) = winning digit / total digits = 1/10
P(2nd digit win) = winning digit / total digits = 1/10
....same for all the digits

so we get

P(5 winning digits) = 1/10  x  1/10  x  1/10  x 1/10  x 1/10 = 1/100,000

or 1: 100,000

ignoramus · Answer

You are incorrect.

The number of possible numbers is 100 000. Jenny has one of them.

So the ODDS of her winning are 99 999 to 1 AGAINST.

But the PROBABILITY of her winning is 1/100 000, or 10^(-5).

Make sure that you know the difference between odds and probability.

What are the steps to solve this probability word problem?

2 Answers