Question

The probability that Latisha orders french fries at lunch is .32 and the probability that she orders a grilled cheese and fries is .65. If the probability that she orders just a grilled cheese sandwich is .76, what is the probability that she will order a grilled cheese and fries?

Answer 1

There is a typo error in the last part of the question. The corrected part is-

"If the probability that she orders just a grilled cheese sandwich is .76, what is the probability that she will order a grilled cheese or fries?"

Answer:

The probability that she will order a grilled cheese sandwich or fries is 0.43.

Step-by-step explanation:

Given:

Probability of ordering fries is, $P(F)=0.32$

Probability of ordering cheese sandwich is, $P(S)=0.76$

Probability of ordering both sandwich and fries is, $P(F\cap S)=0.65$

Probability of ordering cheese sandwich or fries is given by the union of both the events 'F' and 'S' given as $P(F\cup S)$.

Now, using addition theorem of probability, we get:

$P(F\cup S)=P(F)+P(S)-P(F\cap S)\\P(F\cup S)=0.32+0.76-0.65\\P(F\cup S)=0.43$

Therefore, probability of ordering cheese sandwich or fries is 0.43.