A box contains 12 green and 8 blue bulbs .2 bulbs are drawn at random. Find the probability that the

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26 Aug 2021 PROBABILITY

A box contains 12 green and 8 blue bulbs .2 bulbs are drawn at random. Find the probability that they
are of same colour.

OPtion

1) 91/47
2) 47/105
3) 47/95
4) 95/47
5) 96/43
6) 95/43
7) 91/43
8) 93/47
9) 99/47
10) None of the above

Solution

Let S be the sample space
Then n(S) = no of ways of drawing 2 bulbs out of (12+8) = 20c2=20*19/2*1=190
Let E = event of getting both bulbs of same colour
Then, n(E) = no of ways (2 bulbs out of 12) or (2 bulbs out of 8)
=12C2+ 8C2=(132/2)+(56/2) = 66+28 = 94
Therefore, P(E) = n(E)/n(S) = 94/190 = 47/95

Correct Option: 3 Best Solution (4)

Billal Hossain   3 years AGO

Number of possible ways n(S)= 20c2= 20!/2!18!= 190
Number of ways both are same colour n(E)= 12c2+8c2= 66+28=94
Therefore, probability of both bulbs are same colour p(E)= n(E)/n(S)
= 94/190= 47/95
Hence, My option is (3)

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SAYAN CHATTERJEE   3 years AGO

12/20*11/19+8/20*7/19
= 47/95.
Option 3.

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RAMADURAI NATESAN   3 years AGO

ans = 12*11/20*19 + 8*7 / 20*19 = 47/95

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G.S.Kantharao   3 years AGO

12c2+8c2/20c2=132+56/380
=188/380=47/95
My option is 3👈

Like? Yes | No (1)