math question - probability

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My daughter is preparing for the ACT test, and she asked me about a question on her practice test. I don't know how to go about this problem...hoping someone here can explain it.
"The Smiths plan to roof their cabin on 2 consecutive days. During the week they plan to roof the cabin, there is a 20% chance of rain each day. Assuming that the chance of rain is independent of the day, what is the probability that it will rain both days?"
The answer key shows 4% as the correct answer. If someone can tell us how to solve the problem, we would be appreciative.
 
Stolen from Google:

Just multiply the probability of the first event by the second. For example, if the probability of event A is 2/9 and the probability of event B is 3/9 then the probability of both events happening at the same time is (2/9)*(3/9) = 6/81 = 2/27.

By this method, you have two events with 1/5 probability of occurring. 1/5*1/5=1/25 or 4%.
 
Belker is correct, The probability of two independent events is calculated by multiplying the probability of each event against the other. Of course weather days are not independent events but I guess it’s close enough.
 
OK, I understand now. I'm pretty good at math in general, but never learned much about probability. Thanks, all!
 
P(rain day 1) * P(rain day 2) = (.20)*(.20) = .04 = 4%
Similarly, since the probability of no rain each day is 1-0.2=0.8, then the probability of no rain either day is 0.8×0.8=0.64. The probability of rain only on the second day is 0.8×0.2=0.16. Same for only the first. Thus, the chance for both days, plus the chance for neither, plus only the first, plus only the second equals 0.04+0.16+0.16+0.64= 1.00=certainty. Amazing, huh?!
 
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OK, I understand now. I'm pretty good at math in general, but never learned much about probability. Thanks, all!

I took a class series in probability. It was an undergraduate level in terms of complexity, but it was called a graduate level "applied math" class for meeting graduate degree requirements.

This question is pretty simple. But there were far more complicated equations for figuring out different types of probability. I don't remember any of it.
 
Belker is correct, The probability of two independent events is calculated by multiplying the probability of each event against the other. Of course weather days are not independent events but I guess it’s close enough.
Correct. If the rain on Day1 happens at 11:59:59 PM, then the probability of rain on both days is close to or equal to 1, or 100%

Assuming that the chance of rain is independent of the day
Then is 4% as the other users answered.
 
Another example is the coin flip. What is probability you flip a fair coin twice and get heads both times?

We know if we flip a coin twice we can only get 4 outcomes, hh, tt, ht, th. Each with equal probability of 0.25. Or 0.5 x 0.5.
 
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