I'll just do part (a).  Try using the same principle to do part (b) by 
yourself.  If you have trouble, tell me in the thank-you note form below 
and I'll get back to you by email.
A game is such that a fair die is rolled repeatedly until a '6' is obtained. Find the probability that
(a) (i)   the game ends on the third roll,
 

 
(ii)  the game ends on the fourth roll,



(iii) the game ends by the fourth roll.
We add the probabilities of the four mutually exclusive events,
using the same procedure above to calculate the probabilities
that the games end on the 1st roll or 2nd roll, and use the above
two probabilities for it ending on the 3rd or 4th 



Edwin
 

RELATED QUESTIONS

Solve the problem.
1) If a fair die is rolled repeatedly until a ʺtwoʺ... (answered by josmiceli)

A and B play a game as follows: an ordinary die is rolled and if a “six” is obtained then  (answered by Boreal)

A fair die is rolled. Find the probability that the number obtained is not greater than... (answered by joyofmath)

A fair die is rolled three times; Y is the sum of the three numbers obtained. Find the... (answered by stanbon,robertb)

A six sided fair die is rolled. Find the probability that the die shows a number smaller... (answered by ikleyn)

A fair die is rolled  times. What is the probability that a  is obtained on at least one... (answered by Boreal,Alan3354)

if a single fair die is rolled, find the probability of a 4 given that the number rolled... (answered by ewatrrr)

In a carnival game a single die is rolled.  If the number that shows on top is odd, you... (answered by robertb)

You toss a fair 6-sided die 5 times. Find the probability that a three is never rolled.  (answered by ewatrrr,solver91311)