Latest TCS Aptitude Question SOLUTION: There are two box,one containing 10 red balls and the other containing 10 green balls. You are allowed to move the balls between the boxes so that when you choose a box at random a

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(#M40000581) TCS Numerical Ability question Keep an EYE

There are two box,one containing 10 red balls and the other containing 10 green balls. You are allowed to move the balls between the boxes so that when you choose a box at random and a ball at random from the chosen box, the probability of getting a red ball is maximized. This maximum probability is
a) 3/4
b) 37/38
c) 1/2
d) 14/19

Asked In TCS Sumandeep Ghosh (13 years ago)

Solved Dr.Dipin Singh Read Solution (5)

Is this Puzzle helpful?   (28)   (4) Submit Your Solution Probability

Read Solution (5) :

Dr.Dipin Singh  (13 years ago)

14/19

To maximise probability of red ball,
Move 9 red balls in other box such that one box contains 1 red ball and other box contains 9 red and 10 green balls,

then

probability of getting red ball = 1/2 *1 + 1/2*9/19 = 1/2+9/38= 28/38=14/19

Is this solution Helpfull? Yes (120) | No (9)  

vidhya  (13 years ago)

probability of choosing one box 1/2
prob of choosing red ball from green ball 1/2
rest 9/19
so,1/2+1/2*(9/19)=14/19

Is this solution Helpfull? Yes (19) | No (2)  

kewal  (13 years ago)

1/2.

probability of choosing box with red balls is 1/2 and choosing red ball from that box is 1.
so final probability = 1/2

Is this solution Helpfull? Yes (5) | No (39)  

abhisek banerjee  (9 years ago)

see arun sharma book dipin right soultion!

Is this solution Helpfull? Yes | No   

shamsheer  (8 years ago)

the probability for selecting red box is 1/2 but randomly if we select green box, the probability will be 0.
so, total probability for this case is 0.5.

now consider the other case, 9 red balls are transferred to green ball box. now total balls in that box will be 19.

total probability = probability to select 1st box + probability to select 2nd box

= (1/2)*(1C1/1C1)+(1/2)*(9C1/19C1)

= (1/2)*(1+9/19)

= (1/2)*(28/19)

= 14/19

Is this solution Helpfull? Yes | No   

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