Probability Worksheet Solution13





In this page probability worksheet solution13 we are going to see solution of some practice questions of the probability worksheet.

Question 12

A two digit number is formed with the digits 2,5,9 (repetition is allowed). Find the probability that the number is divisible by 2 or 5.

Solution:

Sample space = {22,25,29,55,52,59,99,92,95}

             n (S) = 9

Let A be the event of getting a number which is divisible by 2

 A = {22,52,92}

 n (A) = 3

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

        = 3/9

Let B be the event of getting a number which is divisible by 5

  B = {25,55,95}

 n (B) = 3

 P (B) = n (B)/n (S)

         = 3/9

Since the events A and B are mutually exclusive events,then

P (A ∩ B) = 0

P (A U B) = P (A) + P (B) - P (A ∩ B)

             = (3/9) + (3/9) - 0

             = (3 + 3)/9

             = 6/9

             = 2/3


Question 13

Each individual letter of the word "ACCOMMODATION" is written in a piece of paper,and all 13 pieces of papers are placed in a jar. If one piece of paper is selected at random from the jar,find the probability that

(i) The letter "A" or "O" is selected

(ii) The letter "M" or "C" is selected

Solution:

sample space = {A,C,C,O,M,M,O,D,A,T,I,O,N}

Number of individual letter in the word "ACCOMMODATION" is 13

n (S) = 13

(i) The letter "A" or "O" is selected

Let A be the event of selecting a letter be "A"

 n (A) = 2

 P (A) = n (A)/n (S)

        = 2/13

Let B be the event of selecting a letter be "O"

 n (B) = 3

 P (B) = n (B)/n (S)

         = 3/13

Since both the events A and B are mutually exclusive events,then

P (A ∩ B) = 0

P (A U B) = P (A) + P (B) - P (A ∩ B)

             = (2/13) + (3/13) - 0

             = (2 + 3)/13

             = 5/13

(ii) The letter "M" or "C" is selected

Let A be the event of selecting a letter be "M"

 n (A) = 2

 P (A) = n (A)/n (S)

        = 2/13

Let B be the event of selecting a letter be "C"

 n (B) = 2

 P (B) = n (B)/n (S)

         = 2/13

Since both the events A and B are mutually exclusive events,then

P (A ∩ B) = 0

P (A U B) = P (A) + P (B) - P (A ∩ B)

             = (2/13) + (2/13) - 0

             = (2 + 2)/13

             = 4/13

probability worksheet solution13 probability worksheet solution13