SOLUTION: A bin contains 25 lightbulbs, 5 of which are in good condition and will function for at least 30 days, 10 of which are partially defective and will fail in their second day of use,

Question 466594: A bin contains 25 lightbulbs, 5 of which are in good condition and will function for at least 30 days, 10 of which are partially defective and will fail in their second day of use, 10 will not light up. Given that a randomly chosen bulb initially lights, what is the probability it will still be working after one week?
I was thinking that the prob. of picking a lightbulb that initially lights is 15/25. And the prob. that it will work more than a week is 15/25 * 5/25. Am i wrong thinking this way?
Answer by sudhanshu_kmr(1152) (Show Source): You can put this solution on YOUR website!

Bulb will still be working after one week if it is one of 5 good bulb.
probability = 5/25 = 1/5
yes, thinking that way is wrong.

you are welcome to get online free help: sudhanshu.cochin@gmail.com
RELATED QUESTIONS
A bin contains 25 lightbulbs, 5 of which are in good condition and will function for at... (answered by sudhanshu_kmr)

I randomly take three lightbulbs from a box containing 80 lightbulbs of which 5 are... (answered by ewatrrr)

Find the indicated probability. A bin contains 77 light bulbs of which 12 are... (answered by edjones)

A bin contains 78 light bulbs of which 4 are defective. If 5 light bulbs are randomly... (answered by Boreal)

A bin contains 100 balls, of which 25 are red, 40 are while and 35 are black. If two... (answered by stanbon)

A bin contains 75 light bulbs, 5 of which are defective. If 5 light bulbs are randomly... (answered by ikleyn)

A bin holds 20 components, 4 in which are defective. An engineer selects 5 components to (answered by stanbon)

A shipment contains 100 items, 20 of which are defective. You randomly select 10 items... (answered by ewatrrr)

A farmer in the Midwest has 1,000 acres of land on which she intends to plant corn,... (answered by ikleyn)