Probability Worksheet Solution6





In this page probability worksheet solution6 we are going to see solution of some practice questions of the probability worksheet.

Question 16

A jar contains 54 marbles each of which is in one of colors blue, green and white. The probability of drawing a blue marble is 1/3 and the probability of drawing a green marble is 4/9.How many white marbles does the jar contain?

Solution:

Total number of marbles = 54

Sample space n(s) = 54

Let A be the event of getting blue marble

So probability of getting blue marble is P(A) = 1/3

Let B be the event of getting green marble

So probability of getting green marble is P(B) = 4/9

To find the probability of getting white marble we have to subtract sum of getting blue and green marbles from 1.

Let C be the event of getting white marble

So probability of getting blue marble is P(C) = ?

P(A) + P (B) + P (C) = 1

 1/3 + 4/9 + P (C) = 1

 (3 + 4)/9 + P (C) = 1

       7/9 + P (C) = 1

                P (C) = 1 - (7/9)

                P (C) = (9 - 7)/9

               P (C) = 2/9

Now let us write the formula for P(C) that is n(C)/n(S). There must be 54 in the denominator for that we have to multiply the whole fraction by 6. So that we will get 12/54.

n(C) = 12

Therefore the number of white marbles is 12.

Therefore the number of white marbles is 12.


Question 17

A bag consists of 100 shirts of which 88 are good. 8 have minor defects and 4 have major defects. A trader A will accept only the shirts which are good, but the trader B will not accept the shirts which have major defects. One shirt is drawn at random. What is the probability that is acceptable by (i)  A  (ii) B

Solution:

Total number of shirts = 100

                        n (s) = 100

Number of good shirts = 88

Number of which are having major defects = 4

A will accept only the shirts which are good

(i) Let A be the event that A will accept shirts

 n (A) = 88

Probability of getting good shirts,P (A) = n (A)/n (S)

                                              P (A) =  88/100

                                              P (A) = 44/50

(ii) Let B be the event that B will accept shirts

B will not accept the shirts which have major defects. From this statement we can understand that B will accept the good shirts and the shirt which are having minor defects

            n (B) = 88 + 8

here 88 are number of good shirts and 8 represents number of shirts which are having minor defects

So, n (B) =  96

Probability that B will accept a shirt, P(B) = n (B)/n (S)

                                                  P (B) =  96/100

(i)  Probability of getting good shirts,P (A) = 44/50

(ii) Probability that B will accept a shirt, P(B) = 96/100

probability worksheet solution6 probability worksheet solution6 probability worksheet solution6