Latest TCS Aptitude Question SOLUTION: A bag contains 6 balls of one or more colours. A ball is picked and is found to be red. What is the probability that the bag initially had exactly 6 red balls? option a) 2/7 b) 1/

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(#M40021565) TCS Numerical Ability question Keep an EYE

A bag contains 6 balls of one or more colours. A ball is picked and is found to be red. What is the probability that the bag initially had exactly 6 red balls?
option
a) 2/7
b) 1/5
c) 3/5
d) 4/5

Asked In TCS Tanu (11 years ago)

Unsolved Read Solution (4)

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karthigabalamurugan  (11 years ago)

If we have 1 red ball then the probability of drawing 1 red ball out of 6 balls is 1/6

If there are 2 red balls then the probability of drawing 1 red ball out of them is 2c1/6

similarly the other cases 3/6 4/6 5/6 6/6..

Now the probability of drawing 1 red ball when all the six are red is
[6/6]/[(1/6)+(2/6)+(3/6)+(4/6)+(5/6)+(6/6)]
6/21=2/7..

Is this solution Helpfull? Yes (15) | No (10)  

tarun  (11 years ago)

tanu are this question asked in tcs ??????

Is this solution Helpfull? Yes (3) | No (6)  

pramod sharma  (11 years ago)

as we know, possibility of exactly 6 red ball is 1 and total possible outcomes is 6 because one ball is red (given) now 6 cases are..1) remaining 5 balls are also red 2) 4 out of the remaining 5 are red 3) 3 out of the remaining 5 balls are red 4) 2 out of the remaining 5 balls are red 5) 1 out of the remaining 5 balls are red 6) none out of 5 balls is red.....therefore-
probability= 1/6.....therefore answer is none of these..

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pravallika  (6 years ago)

can anyone explain it?

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