Shouldn't the probability of the last question be
5/20 * 9/19
( Probability that card is divisible by4 ) * ( probability that card is even )
if this is not correct then please provide an explaination. It is so frustrating that araspai has not posted the answer.
No. We are already GIVEN that the first card is divisible by 4. Hence, it already happened with probability 1.
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993