Latest TCS Aptitude Question SOLUTION: A and B roll a pair of dice. A wins if he roll 6 and B wins if he rolls 7. They continue starting with A till one of them throws their respective number. What is the probability th

• Placement Papers
• /
• TCS
• /
• Numerical Ability
• /
• Probability

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40038993) TCS Numerical Ability question Keep an EYE

A and B roll a pair of dice. A wins if he roll 6 and B wins if he rolls 7. They continue starting with A till one of them throws their respective number. What is the probability that A wins?

Asked In TCS payel (9 years ago)

Unsolved Read Solution (8)

Is this Puzzle helpful?   (3)   (2) Submit Your Solution Probability

Read Solution (8) :

shivam  (9 years ago)

let getting6 event be x and getting7 event be y.
so, P(x)= 5/36 & P(y)= 6/36=1/6
P(x)complement = 1- 5/36 = 31/36
P(y)complement = 1- 6/36 = 5/6
let Z be winning probability
so, P(z)= 5/36 + 31/36.5/6.5/36 + 31/36.5/6.31/36.5/6.5/36 + .... infinity
= 30/61

Is this solution Helpfull? Yes (12) | No (3)  

Abhas  (9 years ago)

5/36
6 can be rolled as 1,5 5,1 2,4 4,2 and 3,3

Is this solution Helpfull? Yes (5) | No (1)  

SindhuMallikarjuna  (9 years ago)

let winning probability be p and losing probability be q.
A B
p=3/36;q=30/36; p=6/36;q=30/36;
P(Win A)=p+(q^2*p)+(q^2*q^2*p)+.....
taking p as common
P(Win A)=p[1+q^2+(q^2)^2+....)
terms are in GP
hence sum =p[1/(1-q^2)]
therefore general formula for prob of win A is p[1/(1-q^2)]
Since here losing probabilities are different we take
P(Win A)=p/[1-(q1*q2)]
=>(3/36)/[1-(33/36)(30/36)]
Solving this we get 13/24

Is this solution Helpfull? Yes (1) | No (3)  

manish  (9 years ago)

1/6
6/36 becomes 1/6

Is this solution Helpfull? Yes | No   

Swayanti Bhaumik  (9 years ago)

is it 2/3?
It is forming an infinte series...

Is this solution Helpfull? Yes | No   

nisha kumari  (9 years ago)

two dice thrown sample space will be 36 and A's winning possibilties are 6
=> 6/36= 1/6.
what is the correct answer?

Is this solution Helpfull? Yes | No   

Jyothi Gaduputi  (9 years ago)

1/2 correct answer

Is this solution Helpfull? Yes | No   

raviteja  (9 years ago)

There are 5 ways of obtaining 6 {(1,5), (5, 1), (2, 4), (4, 2), (3, 3)}
and Sample space while throwing 2 dice = 6×6 = 36
So P(E1)=5/36 and P(E1)=1−536=31/36

P(E2)=6/36 and P(E2)=1−16=5/6

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.