Question

Each day, Stu's probability of being on time to work is 0.1. Each day is independent of the other days. What is the probability that Stu will be on time this week on Monday, Tuesday, and Wednesday?

Answer 1

.001 or 1/1000

Explanation:

Comment

The idea behind this question is like flipping a coin and getting either heads or tails. The probability does not depend on a previous through if the coin is an honest coin.

So if you toss the coin 3 times, and you want to get all three tosses to be heads, there are 8 ways that you can throw 3 coins. Only 1 of the eight will give three heads, so the answer is 1/8.

This is the same kind of problem. He goes to work on 3 days, each day doesn't depend on what happened on any other day.

Probability(3 days on time) = 0.1 * 0.1 * 0,1 = 0.001 or 1/1000