MCQ 11 Mark
In a city 20 percent of the population travels by car, 50 percent travels by bus and 10 percent travels by both car and bus. Then persons travelling by a car or bus is
- ✓60 percent
- B80 percent
- C70 percent
- D40 percent
Answer
View full question & answer→Correct option: A.
60 percent
(a) 60 percent
Explanation: Let A denote the set of persons traveling by car, B denotes the set of persons traveling by bus, then
$n(A)=20, n(B)=50, n(A \cap B)=10$
$\therefore \mathrm{n}(\mathrm{A} \cup \mathrm{B})=\mathrm{n}(\mathrm{A})+\mathrm{n}(\mathrm{B})-\mathrm{n}(\mathrm{A} \cap \mathrm{B})$
$=20+50-10=60$
Explanation: Let A denote the set of persons traveling by car, B denotes the set of persons traveling by bus, then
$n(A)=20, n(B)=50, n(A \cap B)=10$
$\therefore \mathrm{n}(\mathrm{A} \cup \mathrm{B})=\mathrm{n}(\mathrm{A})+\mathrm{n}(\mathrm{B})-\mathrm{n}(\mathrm{A} \cap \mathrm{B})$
$=20+50-10=60$
