Alexander L. answered • 05/23/21
Physics Ph.D. Student Tutoring in Math and Physics
Hi Sam,
In order for this problem to have a knowable answer, I think we have to assume that Robert will only propose once to Kate, and she either says yes or no. For a situation like this, the probability of both events happening is equal to the two individual probabilities multiplied together.
For example, let's say that I flip a coin. If it's heads, then I flip the coin again. If I get a second heads, I get $100. What is the probability I get $100? Well, I have a 50-50 chance of getting the first heads, and only then do I have a 50-50 chance of getting a second heads. If I played this game 1000 times, I would only flip the second coin about half the time (around 500), and then I'd only get the money in half of those cases (around 250, one-quarter the time). So the probability of winning $100 is (1/2) x (1/2) = (1/4).
Try using the same logic with the two probabilities in the problem: 0.55 and 0.85.
Sam L.
I did 0.55 x 0.85 = 187/400 odds, A = h/k-h, 187/400-187 = 187/213, so therefore 187:213.05/23/21
Alexander L.
It's always good to check! You actually only need to do the first step there - the answer is 0.55 x 0.85 = 187/400, or 0.4675. I'm not sure what the second step you wrote out is for.05/23/21
Sam L.
its for finding the odds, the formula states, If P(A) = h/k, then odds in favor of A = h/k - h, so you would put in it ratio form. I also had another similar question like this where you had to do that.05/23/21
Alexander L.
I see what you mean! I must have glossed over that it was asking for odds. Good work!05/23/21
Sam L.
It's okay! So overall my answer would be correct? (Including ratio)05/23/21
Sam L.
Thank you so much, so would the answer be 187:213? I want to check my answer if that's okay!05/23/21