Advertisements
Advertisements
प्रश्न
Form a group of 4 men, 4 women and 3 children, 4 persons are selected at random. Find the probability that, no child is selected.
उत्तर
The group consists of 4 men, 4 women and 3 children, i.e., 4 + 4 + 3 = 11 persons.
4 persons are to be selected from this group.
∴ 4 persons can be selected from 11 persons in 11C4 ways.
∴ n(S) = 11C4
Let event A: No child is selected.
∴ 4 persons can be selected from 4 men and 4 women, i.e., from 8 persons in 8C4 ways.
∴ n(A) = 8C4
∴ P(A) = `("n"("A"))/("n"("S"))`
= `(""^8"C"_4)/(""^11"C"_4)`
= `(8 xx 7 xx 6 xx 5)/(11 xx 10 xx 9 xx 8)`
= `1680/7920`
= `7/33`
APPEARS IN
संबंधित प्रश्न
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
Three cards are drawn from a pack of 52 cards. Find the chance that two are queen cards and one is an ace card
Three cards are drawn from a pack of 52 cards. Find the chance that all are from the same suit
Find the probability of getting both red balls, when from a bag containing 5 red and 4 black balls, two balls are drawn, without 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
4 letters are to be posted in 4 post boxes. If any number of letters can be posted in any of the 4 post boxes, what is the probability that each box contains only one letter?
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
Two fair dice are thrown. Find the probability that number on the upper face of the first die is 3 or sum of the numbers on their upper faces is 6
A bag contains 5 red, 4 blue and an unknown number m of green balls. If the probability of getting both the balls green, when two balls are selected at random is `1/7`, find m
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 5 girls and 2 boys, then the probability that no two boys are sitting together for a photograph is
Select the correct option from the given alternatives :
Two dice are thrown simultaneously. Then the probability of getting two numbers whose product is even 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
Solve the following:
An urn contains 5 red balls and 2 green balls. A ball is drawn. If its green, a red ball is added to the urn and if its red, a green ball is added to the urn. (The original ball is not returned to the urn). Then a second ball is drawn. What is the probability that the second ball is red?
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 ______
If three dices are thrown then the probability that the sum of the numbers on their uppermost faces to be atleast 5 is ______.
Let f(x) = `{{:(1/x^2",", 1 < x < oo"," "be the p.d.f of"),(0",", "otherwise"):}`
a r.v. X. If C1 = {x : 1 < x <2} and C2 = {x : 4 < x < 5}, then P(C1 ∪ C2) =______.
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 ______.
