Question

Xerxes, Murray, Norah, Stav, Zeke, Cam, and Georgia are invited to a dinner party. They arrive in a random order and all arrive at different times. What is the probability that Xeres arrives first?

Answer in decimal form. Round to 3 decimal places as needed.

Answer 1

0.143

Explanation:

From counting principle, we can say that:

There are 7! ways of the 7 people to arrive first. Any one of them can come first. But, what is the probability that Xerxes with arrive first?

We take that Xerxes is the first one to arrive, then from the 7 - 1 = 6 remaining people, they can arrive in 6! ways. So

Probability Xerxes arrives first = 6!/7! = 0.1429

Rounding to 3 decimal places, it will be:

Probability Xerxes arrives first = 0.143