SOLUTION: Alex has an 80% chance of passing a test Brad has a 60% chance of passing a test What is the probability that Alex and Brad will both fail the test? My Attempt: i done 20/

Algebra ->  Probability-and-statistics -> SOLUTION: Alex has an 80% chance of passing a test Brad has a 60% chance of passing a test What is the probability that Alex and Brad will both fail the test? My Attempt: i done 20/      Log On


   

Question 1117984: Alex has an 80% chance of passing a test
Brad has a 60% chance of passing a test
What is the probability that Alex and Brad will both fail the test?

My Attempt: i done 20/100 x 40/100 = 800/100 which is 8%
However the mark scheme says that is not correct.
The mark scheme says 20/100 x 20/100 = 400/100 = 4%
How did they get that and if it is wrong what is the right answer?
Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.

        The correct solution is as follows: 


The probability that Alex fails is  1 - 0.8 = 0.2.


The probability that Brad fails is  1 - 0.6 = 0.4.


The probability that both fail  is  0.2*0.4 = 0.08 = 8%.