Question

A bin contains 25 light bulbs, 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, and 10 of which are totally defective and will not light up. Given that a randomly chosen bulb initially lights what is the probability that it will still be working after one week?

Answer 1

Answer:

The probability that it will still be working after one week is $\frac{1}{5}$

Step-by-step explanation:

Given :

Total number of bulbs = 25

Number of bulbs which are good condition and will function for at least 30 days = 5

Number of bulbs which are partially defective and will fail in their second day of use = 10

Number of bulbs which are totally defective and will not light up = 10

To find : What is the probability that it will still be working after one week?

Solution :

First condition is a randomly chosen bulb initially lights,

i.e. Either it is in good condition and partially defective.

Second condition is it will still be working after one week,

i.e. Bulbs which are good condition and will function for at least 30 days

So, favorable outcome is 5

The probability that it will still be working after one week is given by,

$\text{Probability}=\frac{\text{Favorable outcome}}{\text{Total number of outcome}}$

$\text{Probability}=\frac{5}{25}$

$\text{Probability}=\frac{1}{5}$