# Math Help - Probability equations

1. ## Probability equations

I have to solve the following question:

1, What is the probability of rain on any given working day (Mon-Fri) given that that probility from records suggest 30%.

i, the probability of no rain on 3 consecutive working days

ii, the probaility that there will be rain on at least 1 of 4 consecutive days.

how is this calculated and what is the equation for doing so? Please be simple and detailed in the response as I'm picking this stuff up as I go along.

Colin

2. ## Re: Probability equations

Originally Posted by colinb0
I have to solve the following question:
1, What is the probability of rain on any given working day (Mon-Fri) given that that probility from records suggest 30%.
i, the probability of no rain on 3 consecutive working days
ii, the probaility that there will be rain on at least 1 of 4 consecutive days.
ii) $1-(0.7)^4$ WHY?

What is the answer to i. ?