n(C) = 70 (number of people who like coffee)
n(T) = 60 (number of people who like tea)
n(C ∩ T) = 45 (number of people who like both coffee and tea)
We need to find n(C' ∩ T'), which represents the number of people who like neither coffee nor tea.
Using the formula:
n(C ∪ T)' = n(U) - n(C ∪ T)
We know:
n(U) = 100
n(C ∪ T) = n(C) + n(T) - n(C ∩ T) = 70 + 60 - 45 = 85
Therefore,
n(C' ∩ T') = 100 - 85 = 15