Thread: Probability

Six cards labelled A, B, C, D, E and F are drawn one at a time from a hat. What is the probability that card A or card E will be the third card drawn?

How do I even start this?

the first card drawn cannot be card a or e. second card cannot be card a or e also. then probability of the third card drawn is card a or e.

Is there an easy way to find the answer without listing out all the possibilities?

Six cards labelled A, B, C, D, E and F are drawn one at a time from a hat. What is the probability that card A or card E will be the third card drawn?

How do I even start this?
= (a or e is not chosen)(a or e is not chosen for the second time)(a or e is chosen)
= (4/6)(3/5)(2/4)
= 1/5

You dont have any information about cards one and two, therefore the probability that the third card is A or E is the same as the probability that the first card is A or E = 1/3

Originally Posted by z1llch

Six cards labelled A, B, C, D, E and F are drawn one at a time from a hat. What is the probability that card A or card E will be the third card drawn?

How do I even start this?
= (a or e is not chosen)(a or e is not chosen for the second time)(a or e is chosen)
= (4/6)(3/5)(2/4)
= 1/5

A or E can be drawn on the first or second time, but they cannot both be drawn before the first time. So you have the add the probability that A is drawn on the first time or second time and E on the third time and also that E is drawn before the third time and A on the third time.