Question

In a certain city, 80% of the residents like coffee or tea . 30% of them like coffee. 60%

percent of them like tea. What is the probability of residents like (a) both? (b) tea but not

coffee? (c) only coffee (d) neither tea nor coffee ?​

Answer 1

a =10% b=50% c=20% d=20%

Explanation:

n(CuT)=n(C)+n(T)-n(CnT)

so n(CnT)=10%

for b

tea but not coffee =nonly(T)

=n(T)-n(TnC)

=50%

for c

only coffee=nonly(C)

=n(C)-n(CnT)

=20%