Advertisements
Advertisements
प्रश्न
A class consists of 10 boys and 8 girls. Three students are selected at random. What is the probability that the selected group has all girls?
उत्तर
Total number of students = (10 + 8) = 18
Let S be the sample space.
Then n(S) = number of ways of selecting 3 students out of 18 = 18C3 ways
Out of eight girls, three girls can be selected in 8C3 ways.
∴ Favourable number of events, n(E) = 8C3
Hence, required probability =\[\frac{^{8}{}{C}_3}{^{18}{}{C}_3} = \frac{8 \times 7 \times 6}{18 \times 17 \times 16} = \frac{7}{102}\]
APPEARS IN
संबंधित प्रश्न
Describe the sample space for the indicated experiment: A coin is tossed three times.
Suppose 3 bulbs are selected at random from a lot. Each bulb is tested and classified as defective (D) or non-defective (N). Write the sample space of this experiment?
A coin is tossed. If it shows a tail, we draw a ball from a box which contains 2 red and 3 black balls. If it shows head, we throw a die. Find the sample space for this experiment.
A die is thrown repeatedly until a six comes up. What is the sample space for this experiment?
A coin is tossed once. Write its sample space
If a coin is tossed three times (or three coins are tossed together), then describe the sample space for this experiment.
A coin is tossed and then a die is thrown. Describe the sample space for this experiment.
A coin is tossed twice. If the second draw results in a head, a die is rolled. Write the sample space for this experiment.
An experiment consists of boy-girl composition of families with 2 children.
What is the sample space if we are interested in knowing whether it is a boy or girl in the order of their births?
2 boys and 2 girls are in room P and 1 boy 3 girls are in room Q. Write the sample space for the experiment in which a room is selected and then a person.
A die is thrown repeatedly until a six comes up. What is the sample space for this experiment.
Three coins are tossed once. Describe the events associated with this random experiment:
A = Getting three heads
B = Getting two heads and one tail
C = Getting three tails
D = Getting a head on the first coin.
(iii) Which events are compound events?
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is neither a heart nor a king
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is spade or an ace
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is neither an ace nor a king
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is a diamond card
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is not a diamond card
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is not a black card.
Tickets numbered from 1 to 20 are mixed up together and then a ticket is drawn at random. What is the probability that the ticket has a number which is a multiple of 3 or 7?
A bag contains 6 red, 4 white and 8 blue balls. if three balls are drawn at random, find the probability that one is red, one is white and one is blue.
A bag contains 7 white, 5 black and 4 red balls. If two balls are drawn at random, find the probability that both the balls are white
Find the probability that in a random arrangement of the letters of the word 'SOCIAL' vowels come together.
The letters of the word' CLIFTON' are placed at random in a row. What is the chance that two vowels come together?
The letters of the word 'FORTUNATES' are arranged at random in a row. What is the chance that the two 'T' come together.
A committee of two persons is selected from two men and two women. What is the probability that the committee will have one man?
A committee of two persons is selected from two men and two women. What is the probability that the committee will have two men?
20 cards are numbered from 1 to 20. One card is drawn at random. What is the probability that the number on the cards is not a multiple of 4?
A class consists of 10 boys and 8 girls. Three students are selected at random. What is the probability that the selected group has at least one girl?
A single letter is selected at random from the word 'PROBABILITY'. What is the probability that it is a vowel?
What is the probability that a leap year will have 53 Fridays or 53 Saturdays?
A die is rolled, then the probability that a number 1 or 6 may appear is
6 boys and 6 girls sit in a row at random. The probability that all the girls sit together is
How many two-digit positive integers are multiples of 3?
Three of the six vertices of a regular hexagon are chosen at random. What is the probability that the triangle with these vertices is equilateral?
Suppose an integer from 1 through 1000 is chosen at random, find the probability that the integer is a multiple of 2 or a multiple of 9.
A bag contains 20 tickets numbered 1 to 20. Two tickets are drawn at random. The probability that both the numbers on the ticket are prime is ______.
