English

Given Two Independent Events A And B Such That P (A) = 0.3 And P (B) = 0.6. Find (V) P (A ∪ B) - Mathematics

Advertisements
Advertisements

Question

Given two independent events A and B such that P (A) = 0.3 and P (B) = 0.6. Find P (A ∪ B).

Sum

Solution

\[\text{ Given } : \]
\[\text{ A and B are independent events } .\]
\[P\left( A \right) = 0 . 3\]
\[P\left( B \right) = 0 . 6\]

\[P\left( A \cup B \right) = P\left( A \right) + P\left( B \right) - P\left( A \cap B \right)\]
\[ = 0 . 3 + 0 . 6 - 0 . 18\]
\[ = 0 . 9 - 0 . 18\]
\[ = 0 . 72\]

shaalaa.com
Probability Examples and Solutions
  Is there an error in this question or solution?
Chapter 31: Probability - Exercise 31.4 [Page 54]

APPEARS IN

RD Sharma Mathematics [English] Class 12
Chapter 31 Probability
Exercise 31.4 | Q 6.5 | Page 54

RELATED QUESTIONS

In a set of 10 coins, 2 coins are with heads on both the sides. A coin is selected at random from this set and tossed five times. If all the five times, the result was heads, find the probability that the selected coin had heads on both the sides.


A and B throw a pair of dice alternately. A wins the game if he gets a total of 7 and B wins the game if he gets a total of 10. If A starts the game, then find the probability that B wins


Given that the two numbers appearing on throwing two dice are different. Find the probability of the event 'the sum of numbers on the dice is 4'.


A die is thrown three times, find the probability that 4 appears on the third toss if it is given that 6 and 5 appear respectively on first two tosses.


If A and B are two events such that P (A) = \[\frac{1}{3},\] P (B) = \[\frac{1}{5}\] and P (A ∪ B) = \[\frac{11}{30}\] , find P (A/B) and P (B/A).

 
 
 

A bag contains 25 tickets, numbered from 1 to 25. A ticket is drawn and then another ticket is drawn without replacement. Find the probability that both tickets will show even numbers.


If A and B are two events such that
\[ P\left( A \right) = \frac{1}{2}, P\left( B \right) = \frac{1}{3} \text{ and }  P\left( A \cap B \right) = \frac{1}{4}, \text{ then find } P\left( A|B \right), P\left( B|A \right), P\left( \overline{ A }|B \right) \text{ and }  P\left( \overline{ A }|\overline{ B } \right) .\]


If P (A) = \[\frac{6}{11},\]  P (B) = \[\frac{5}{11}\]  and P (A ∪ B) = \[\frac{7}{11},\]  find

(i) P (A ∩ B)
(ii) P (A/B)
(iii) P (B/A)

A coin is tossed three times. Find P (A/B) in each of the following:

A = At least two heads, B = At most two heads


A die is thrown three times. Find P (A/B) and P (B/A), if
A = 4 appears on the third toss, B = 6 and 5 appear respectively on first two tosses.


Given two independent events A and B such that P (A) = 0.3 and P (B) = `0.6. Find P (A ∩ overlineB ) `.


A and B are two independent events. The probability that A and B occur is 1/6 and the probability that neither of them occurs is 1/3. Find the probability of occurrence of two events.


Given the probability that A can solve a problem is 2/3 and the probability that B can solve the same problem is 3/5. Find the probability that none of the two will be able to solve the problem.

 

The probability that A hits a target is 1/3 and the probability that B hits it, is 2/5, What is the probability that the target will be hit, if each one of A and B shoots at the target?


An urn contains 4 red and 7 black balls. Two balls are drawn at random with replacement. Find the probability of getting 2 blue balls. 


An urn contains 4 red and 7 black balls. Two balls are drawn at random with replacement. Find the probability of getting one red and one blue ball.


The probabilities of two students A and B coming to the school in time are \[\frac{3}{7}\text { and }\frac{5}{7}\] respectively. Assuming that the events, 'A coming in time' and 'B coming in time' are independent, find the probability of only one of them coming to the school in time. Write at least one advantage of coming to school in time.

 

Let A and B be two independent events such that P(A) = p1 and P(B) = p2. Describe in words the events whose probabilities are:  `1 - (1 - p_1 )(1 -p_2 ) `


Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that both the balls are red.


A and B toss a coin alternately till one of them gets a head and wins the game. If A starts the game, find the probability that B will win the game.


A husband and wife appear in an interview for two vacancies for the same post. The probability of husband's selection is 1/7 and that of wife's selection is 1/5. What is the probability that none of them will be selected?

 

 


A bag contains 7 white, 5 black and 4 red balls. Four balls are drawn without replacement. Find the probability that at least three balls are black.

 

A, B and C in order toss a coin. The one to throw a head wins. What are their respective chances of winning assuming that the game may continue indefinitely?


A bag contains 8 marbles of which 3 are blue and 5 are red. One marble is drawn at random, its colour is noted and the marble is replaced in the bag. A marble is again drawn from the bag and its colour is noted. Find the probability that the marble will be
(i) blue followed by red.
(ii) blue and red in any order.
(iii) of the same colour.


A bag contains 3 white and 2 black balls and another bag contains 2 white and 4 black balls. One bag is chosen at random. From the selected bag, one ball is drawn. Find the probability that the ball drawn is white.


An unbiased coin is tossed. If the result is a head, a pair of unbiased dice is rolled and the sum of the numbers obtained is noted. If the result is a tail, a card from a well shuffled pack of eleven cards numbered 2, 3, 4, ..., 12 is picked and the number on the card is noted. What is the probability that the noted number is either 7 or 8?


A bag contains 4 white and 5 black balls and another bag contains 3 white and 4 black balls. A ball is taken out from the first bag and without seeing its colour is put in the second bag. A ball is taken out from the latter. Find the probability that the ball drawn is white.


Three machines E1E2E3 in a certain factory produce 50%, 25% and 25%, respectively, of the total daily output of electric bulbs. It is known that 4% of the tubes produced one each of the machines Eand E2 are defective, and that 5% of those produced on E3 are defective. If one tube is picked up at random from a day's production, then calculate the probability that it is defective.


If A and B are two events write the expression for the probability of occurrence of exactly one of two events.


A speaks truth in 75% cases and B speaks truth in 80% cases. Probability that they contradict each other in a statement, is


Out of 30 consecutive integers, 2 are chosen at random. The probability that their sum is odd, is


Mark the correct alternative in the following question:

\[\text{ If} P\left( A \right) = 0 . 4, P\left( B \right) = 0 . 8 \text{ and } P\left( B|A \right) = 0 . 6, \text{ then } P\left( A \cup B \right) = \]


Mark the correct alternative in the following question:A flash light has 8 batteries out of which 3 are dead. If two batteries are selected without replacement and tested, then the probability that both are dead is


If two events A and B are such that P (A)

 \[\left( \overline{ A } \right)\] = 0.3, P (B) = 0.4 and P (A ∩ B) = 0.5, find P \[\left( B/\overline{ A }\cap \overline{ B } \right)\]. 


Refer to Question 6. Calculate the probability that the defective tube was produced on machine E1.


A and B throw a die alternately till one of them gets a '6' and wins the game. Find their respective probabilities of winning, if A starts the game first.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×