Answer:
1/6
Step-by-step explanation:
P(A) = probability a student buys lunch = 60% = 0.6
P(B) = probability a student buys lunch and dessert = 10% = 0.1
We are looking at the probability that a student buys lunch and dessert on the condition that they already bought lunch. Therefore, we are looking at a conditional probability.
P(B given A) = P(A and B) / P(A)
= 0.1 / 0.6
= 1/6 ≈ 0.167