Question

In the last several weeks, 10 days saw rain and 54 days saw high winds. In that same time period, 56 days saw either rainor high winds. How many days saw both rain and high winds?

Answer 1

We know the number of days that saw rain, n(R) = 10, the number of days that saw high winds, n(W) = 54, and the number of days that saw either rain or high winds, n(R∪W) = 56.

And we need to find the number of days that saw both rain and high winds, n(R∩W).

So, we can use the formula:

`n\mleft(R\cap W\mright)=n(R)+n(W)-n\mleft(R\cup W\mright)`

Thus, we obtain:

`n\mleft(R\cap W\mright)=10+54-56=64-56=8`

Therefore, 8 days saw both rain and high winds.