SOLUTION: I need some help with these questions. Mary and jim are taking the same math class and have a quiz coming up next tuesday. The probability that mary studies is 0.8 and the prob

Question 403928: I need some help with these questions.
Mary and jim are taking the same math class and have a quiz coming up next tuesday. The probability that mary studies is 0.8 and the probability that jim studies is 0.7.
1. If Mary and Jim studying are independent events then waht is the probability that mary and jim both study?
2. What is the probability that mary studies if we know that jim studies?
3. What is the probability that mary studies OR jim does not?
Thanks for your help.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Mary and jim are taking the same math class and have a quiz coming up next tuesday. The probability that mary studies is 0.8 and the probability that jim studies is 0.7.
1. If Mary and Jim studying are independent events then what is the probability that mary and jim both study?:::0.8*0.7
---------------------------------------------------
2. What is the probability that mary studies if we know that jim studies?
P(Mary studies|jim studies) = 0.8 because they are independent
---------------------------------------------------)
3. What is the probability that mary studies OR jim does not?
P(mary does OR jim does not) = P(mary) + p(jim not) -P(mary and Jim does not)
= 0.8 + 0.3 - (0.8*0.3)
---
= 1.1-0.24
---
= 0.86
===========
Cheers,
Stan H.
RELATED QUESTIONS
I have to make up a real number system assessment for math class. And I was wondering if... (answered by solver91311,richwmiller)

I am taking a placement test next week and i need some help with some math. with... (answered by josmiceli,solver91311)

hello, i have a quiz coming up and i need help :) please SHOW work and EXPLAIN how to do... (answered by rfer)

I am in my 50's and taking a online math class. I need some help with this problem if... (answered by Fombitz)

Hi, I am taking an online algebra class as part of my pre-nursing courses. I have been... (answered by checkley71)

Hi I have a 68% overall and my class now I have a test coming up worth 10% and a final... (answered by ankor@dixie-net.com)

I have a HUGE test coming up and I need some help. How do you graph the inequality 2x +... (answered by jim_thompson5910)

could someone please help me with these fraction.These ones are either multiply or... (answered by Alan3354)

I don't get these at all I read loads of web info but none of which makes sense I really... (answered by Fombitz)