Advertisements
Advertisements
प्रश्न
Solve the following:
A family has two children. One of them is chosen at random and found that the child is a girl. Find the probability that both the children are girls
उत्तर
A family has two children.
∴ Sample space S = {BB, BG, GB, GG}
A: First child is a girl.
∴ A = {GB, GG}
∴ P(A) = `2/4 = 1/2`
B: Second child is a girl.
∴ B = {BG, GG}
∴ A ∩ B = {GG}
∴ P(A ∩ B) = `1/4`
Required probability = `"P"("B"/"A")`
= `("P"("A" ∩ "B"))/("P"("A"))`
= `(1/4)/(1/2)`
= `1/2`.
APPEARS IN
संबंधित प्रश्न
A fair die is thrown two times. Find the probability that sum of the numbers on them is 5
A fair die is thrown two times. Find the probability that sum of the numbers on them is at least 8
Two cards are drawn from a pack of 52 cards. Find the probability that one is club and the other is a diamond.
Two cards are drawn from a pack of 52 cards. Find the probability that both are from the same suit.
Two cards are drawn from a pack of 52 cards. Find the probability that one is a heart card and the other is a non-heart card
Find the probability of getting both red balls, when from a bag containing 5 red and 4 black balls, two balls are drawn, with replacement
Letters of the word MOTHER are arranged at random. Find the probability that in the arrangement vowels are always together.
Letters of the word MOTHER are arranged at random. Find the probability that in the arrangement vowels are never together
Letters of the word MOTHER are arranged at random. Find the probability that in the arrangement O is at the begining and end with T
Letters of the word MOTHER are arranged at random. Find the probability that in the arrangement starting with a vowel and end with a consonant
15 professors have been invited for a round table conference by Vice chancellor of a university. What is the probability that two particular professors occupy the seats on either side of the Vice chancellor during the conference
A bag contains 7 black and 4 red balls. If 3 balls are drawn at random find the probability that all are black
Form a group of 4 men, 4 women and 3 children, 4 persons are selected at random. Find the probability that, exactly 2 men are selected
A number is drawn at random from the numbers 1 to 50. Find the probability that it is divisible by 2 or 3 or 10
Select the correct option from the given alternatives :
There are 2 shelves. One shelf has 5 Physics and 3 Biology books and the other has 4 Physics and 2 Biology books. The probability of drawing a Physics book is
Select the correct option from the given alternatives :
Two friends A and B apply for a job in the same company. The chances of A getting selected is `2/5` and that of B is `4/7`. The probability that both of them get selected is
Select the correct option from the given alternatives :
The probability that a student knows the correct answer to a multiple choice question is `2/3`. If the student does not know the answer, then the student guesses the answer. The probability of the guessed answer being correct is `1/4`. Given that the student has answered the question correctly, the probability that the student knows the correct answer is
Solve the following:
A die is loaded in such a way that the probability of the face with j dots turning up is proportional to j for j = 1, 2, .......6. What is the probability, in one roll of the die, that an odd number of dots will turn up?
Ram is visiting a friend. Ram knows that his friend has 2 children and 1 of them is a boy. Assuming that a child is equally likely to be a boy or a girl, then the probability that the other child is a girl, is ______.
Four persons work independently on a task. If the respective probabilities that they will solve it are 1/5, 1/3, 1/7, and 1/6, then the probability that none can solve it is ______
A coin is tossed 9 times. The probability of obtaining at most one head is ______
An unbiased die with faces marked 1, 2, 3, 4, 5 and 6 is rolled four times. Out of four face values obtained, the probability that the minimum face value is not less than 2 and the maximum face value is not greater than 5, is ______.
A coin is tossed 2n times. The chance that the number of times one gets head is not equal to the number of times one gets tail is ______.
Four mangoes and five apples are in a box. If two fruits are chosen at random, then find the probability that one is a mango and other is an apple ______.
If two letters of the word MOTHER are selected at random. Probability that both are consonants is ______.
A cupboard contains 3 pink, 3 black and 5 blue shirts well mixed. A person pulls out 2 shirts at random from cupboard. The probability that they match is ______.
In a simultaneous toss of five coins, the probability of getting exactly four tails is ______.
A die is rolled. If X denotes the number of positive divisors of the outcome then the range of the random variable X is ______.
A die is thrown four times. The probability of getting perfect square in at least one throw is ______.
Probability of guessing correctly atleast 7 out of 10 answers in a ‘True’ or ‘False’ test is equal to ______.
If 15 coupons are numbered 1, 2, 3, ..., 15, respectively. 7 coupons are selected at random one at a time with replacement. The probability that the largest number appearing on a selected coupon is almost 9, is ______.
The probability of India winning a test match against South Africa is 1/2 assuming independence form match to match played. The probability that in a match series India's second win occurs at the third day is ______.
