For a school field trip the students had two options for lunch, a turkey or egg salad sandwich, so it is impossible for a student have both lunches. If the probability that a student chooses a turkey sandwich is 0.10, and the probability that a student chooses an egg salad sandwich is 0.67, what is the probability that a student chooses a turkey or egg salad sanwich?

Answer: 0.77

Step-by-step explanation:

Given : Probability that a student chooses a turkey sandwich is

P (Turkey) = 0.10

Probability that a student chooses an egg salad sandwich is

P (egg salad) = 0.67

Also, it is impossible for a student have both lunches.

∴ P (Turkey and egg salad) = 0

Now, the probability that a student chooses a turkey or egg salad sandwich will be

P (Turkey or egg salad) = P (Turkey) + P (egg salad) - P (Turkey and egg salad)

= 0.10 + 0.67-0 = 0.77

Hence, the probability that a student chooses a turkey or egg salad sandwich = 0.77