Question

A box contains two defective Christmas tree lights that have been inadvertently mixed with eight nondefective lights. If the lights are selected one at a time without replacement and tested until both defective lights are found, what is the probability that both defective lights will be found within three trials? (Round your answer to four decimal places.)

Answer 1

defective lights =2C2

Answer 2

first light is non defective,2 defective,3 defective-->case1
,first defective 2nd non defective,3rd defective-->case2
first defective ,2nd defective,3rd non defective --->case 3

Answer 3

8C1*2C2 so from 8 one non defective and from defective 2

Answer 4

then total 10 you have select 3 so that 10C3

Answer 5

2C2)*(8C1) / (10C3)

Answer 6

now CAN U DO?

Answer 7

yes thank you