00:01
In this problem there are 7 broken, 7 broken right and 20 good devices right in a box.
00:16
Okay, what is the probability that one of the two randomly selected devices without replacement is defective? we want to calculate, we have to choose how many? two, two devices right? so this is given to us right? in total it would be broken plus good devices would be give you the total number of devices is how much? this is 27 right in total.
00:50
Now we need to find out probability, probability p, p would be equals to probability that one of the two randomly selected devices without replacement, without replacement is defective right? remember without replacement right? so how many defective pieces are present? 7.
01:37
So first of all let us say p is equals to here it would be given by p so it would be equals to 2 we need to select.
01:46
One is that means probability remember that probability is nothing but number of favorable like outcomes upon total number of outcomes.
01:59
So here 7 you will be selecting right? you wanted favorable number of outcomes is 7 only.
02:06
Now this is whole divided by 27.
02:10
So this is one probability of selecting one, one device right? being defective right? this is the probability and there are two things right? first is 7 by 27 this will be the probability...