If 2 light bulbs was taken from a collection 12, all but 3 are working.?

Question

Find the probability that 2 are working bulbs:

a) among first 3 bulbs tested

b) when 3 bulbs have been tested, but not before.

Answer 1

7

Answer 2

ans.(a). the probability that 2 bulb are working bulb of the randomly 3 bulb tested is directly proportional to the regularity of electric current in your area.