Question

A carton contains 12 green and 8 blue bulbs. 2 bulbs are drawn at random. Find the probability that they are of same colour?
A. (91/47)
B. (47/105)
C. (47/95)
D. (47/145)

answer with explanation​

Answer 1

Answer:

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

Step-by-step explanation:

Answer 2

Step-by-step explanation:

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