If there is a 90% chance of rain tomorrow and a 70% chance of wind and rain, what is the probability that it is windy, given that it is rainy? Round your answer to the nearest percent.
A) 67%
B) 71%
C) 33%
D) 78%

Question

If there is a 90% chance of rain tomorrow and a 70% chance of wind and rain, what is the probability that it is windy, given that it is rainy? Round your answer to the nearest percent. 
A) 67% 
B) 71% 
C) 33% 
D) 78%

anonymous · Answer

Probability of an event happening = $$\frac{ x }{ y }$$ where in x = Number of ways it can happen and y = Total number of outcomes

anonymous · Answer

it's D right? @Sadworld

anonymous · Answer

The numerator will be: 90% it would rain + 70% would be windy.
Denominator: would be 3 since it can only rain or it can only be windy, or both of them.

anonymous · Answer

Top part has two chances, rain and wind. So the equation should be:$$\frac{ 2 }{ 3 }$$

anonymous · Answer

I'm torn between A and D; if you add all the even together = top would have 3 and bottom have 4.

anonymous · Answer

I'm just unsure if you have to add the event of both happening or not as one event or separate.

anonymous · Answer

it's $$\frac{ 2 }{ 3 }\times100=67~percent~?$$  @Sadworld

anonymous · Answer

Yup.

anonymous · Answer

thnx @Sadworld

anonymous · Answer

I'm sticking with 2/3 since there are a couple things that might happen - it'll rain or it'll be windy - and three possible ways to present itself - only rain, only wind or both.

anonymous · Answer

i got it guys! thank you :)