# If the chances of rain are 40% and 20% for the two days of the weekend, what is the chance that it will rain on at least one of the two days?

##### 2 Answers

The Reqd. Prob.

#### Explanation:

Let

Therefore, by what is given, we have,

The Reqd. Prob.

As regards,

Therefore,

The Reqd. Prob.

We first look at the chance of it **NOT** raining at both days.

#### Explanation:

Saturday: 60% of NO rain, translates to a fraction of

Sunday: 80% of NO rain, a fraction of

Both Sat **AND** Sun No rain means **MULTIPLY** :

So the chance of rain on at least one of the days will be:

**Extra:**

Of this

**Summary:**

- No rain at all: 48%

- Rain one day: 44%

- Rain both days: 8%

Adding up to 100% (this is to check your answer)