Question

Ticket number 1 to 20 are mixed up and then ticket is drown at random ,what is problility the ticken drawn has anumber ,which is multiple of 3 or 5

Answer 1

total number of tickets = 20

multiples of 3 = 3, 6, 9, 12, 15, 18
multiples of 5 = 5, 10, 15, 20

total number of tickets which have numbers that are multiples of 3 and 5 = 10

required probability = 10/20 = 1/2

Hope this helps you

Answer 2

Answer:

Given Sample Space S = {1,2,3,4,5,6,.....,18,19,20}

Number of elements in Sample space n(S) = 20

Let A be event of getting a multiple of 3 or 5;

A =  {3, 6 , 9, 12, 15, 18, 5, 10, 20}

Number of elements in event A n(A) = 9

P(A) = Number of elements in event A / Number of elements in Sample space

P(A) = n(A)/ n(S)

Substituting the values;

P(A) = 9/20 = 0.45

The probability of the ticket drawn has a number which is multiple of 3 or 5 is 0.45