00:01
We are discussing probabilities and we have the heart of a calculator is one or more chips on which thousands of components are etched.
00:09
Chips are mass produced and have a fairly high probability of being defective.
00:13
Suppose that a particular brand of calculator uses two kinds of chips.
00:18
Chip a is a probability of 70 % of being defective while chip b has a probability of 80 % of being defective.
00:25
If one chip of each kind is randomly selected, we need to find the probability, that.
00:32
So what is the probability that both chips are defective? so the probability that both chips are defective, remember we find the probability of a and b is equal to the probability of a times the probability of b.
01:00
So if both chips are defective, it's the probability that a is defective, which is 70 % times the probability that b is defective, which is 80%.
01:17
So the probability that both are defective is 56%.
01:26
Now we need to find the probability that a is not defective.
01:34
So the probability that a is not defective, since the probability that a is defective is 70%...