Question

20 tickets, on which numbers 1 to 20 are written, are mixed thoroughly and then a ticket is drawn at random out of them. find the probability that the number on the drawn ticket is (i) a multiple of 3 or 7 (ii) a prime number

Answer 1

Answer:

Step-by-step explanation:

( i ) a multiple of 3 or 7                

     multiple of 3 or 7 are - 3,6,9,12,16,18

                                            7,14

     now, total=8, no. of tickets =20

     P(E multiple of 3 or 7) = 8/20

                                          = 2/5

( ii ) a prime number

prime no. between 1 and 20 are - 2,3,5,7,11,13,17,19

P ( E ) = 8/20

         = 2/5

Answer 2

The required answer for both the question is 2/5.

Please do refer the attachment for the steps and explanation.