Answer:
a) 179 people shopped at the grocery store or the drug store.
b) 21 people shopped at neither the grocery store nor the drug store
Step-by-step explanation:
I am going to treat these events as Venn sets.
I am going to say that:
Set A: Shopped at the grocery store
Set B: Shoped at the drug store.
121 shopped at the grocery store:
This means that
91 shopped at the drug store:
This means that
33 shopped at both businesses.
This means that
a) How many people shopped at the grocery store or the drug store?
This is
With the values given in the exercise.
179 people shopped at the grocery store or the drug store.
b) How many people shopped at neither the grocery store nor the drug store?
179 of 200 shopped in at least one. So 200 - 179 = 21 shopped at neither.
21 people shopped at neither the grocery store nor the drug store