A box contains 20 cards numbered from 1 to 20. A card is drawn at random from the box. Find the probability that the number on the drawn card is: |
(i) divisible by 2 or 3 |
(ii) a prime number |
Answer:
Total number of outcomes \[=20\] (i) Let \[{{E}_{1}}\] be the event of getting a number divisible by 2 or 3. Then, favourable outcomes = 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 3, 9, 15. Number of favourable outcomes \[=13\] \[\therefore \] P (getting a no. divisible by 2 or 3) \[=P({{E}_{1}})=\frac{13}{20}\] (ii) Let \[{{E}_{2}}\] be the event of getting a prime number. Then, favourable outcomes = 2, 3, 5, 7, 11, 13, 17, 19. Number of favourable outcomes \[=8\] P (getting a prime number) \[=P({{E}_{2}})=\frac{8}{20}=\frac{2}{5}\]
You need to login to perform this action.
You will be redirected in
3 sec