Advertisements
Advertisements
Question
In Adarsh High School, out of 30 students in a class 3 students wear glasses (spectacles). If a student in the class is randomly selected, find the probability that he or she wears glasses (spectacles) by completing the following activity
Activity: There are a total of 30 students in the class.
∴ n(S) = `square`
Event: A selected student wears glasses (spectacles).
∴ n(A) = `square`
P(A) = `square/("n"("S"))` ......[Formula]
P(A) = `square`
Solution
There are a total of 30 students in the class.
∴ n(S) = 30
Event A: selected student wears glasses (spectacles).
∴ n(A) = 3
P(A) = `("n"("A"))/("n"("S"))` ......[Formula]
P(A) = `3/30` = `1/10`
RELATED QUESTIONS
The six faces of a die are marked
The event M is getting a vowel on the upper face of the die when it is tossed. Complete the following activity and find the probability of the event.
`"S" = {square}`
`"n"("S") = square`
`"M" = {square}`
`"n"("M") =square`
`"P"("M") = square/square=square`
Two-digit numbers are formed from the digits 0,1,2,3,4 where digits are not repeated. Find the probability of the events that:
(a) The number formed is an even number.
(b) The number formed is a prime number.
A bag contains 3 red, 3 white, 3 green, and 3 black balls. One ball is picked up from the bag at random. What is the probability that the ball drawn is:
a. white
b. not white.
What is the probability of the event that a number chosen from 1 to 50 is a prime number?
If one die is rolled, then find the probability of the following event by completing the activity.
Event A: The number on the upper face is prime.
Activity: Let ‘S’ be the sample space.
S = {1, 2, 3, 4, 5, 6}
∴ n(S) = 6
Event A: Prime number on the upper face.
A = {`square`}
∴ n(A) = 3
P(A) = `square/(n(S))` .....[Formula]
= `square/6`
∴ P(A) = `1/square`
A card is drawn from a well shuffled pack of 52 playing cards. Find the probability of the event, the card drawn is a red card.
Activity: Let ‘S’ be the sample space.
∴ n(S) = 52
Event A: Card drawn is a red card.
∴ Total red cards = `square` hearts + 13 diamonds
∴ n(A) = `square`
∴ P(A) = `square/(n("S"))` ......[Formula]
P(A) = `26/52`
P(A) = `square`
There are 30 cards in a box, each bearing one of the numbers from 1 to 30. One card is drawn at random from the box. Find the probability of event that the card drawn shows a number which is a multiple of 5
If One coin and one die are thrown simultaneously, find the probability of the following events.
Event B: To get head and an odd number
What is the probability that a leap year has 53 Sundays?
A box contains 36 cards, bearing only one number from 1 to 36 on each. If one card is drawn at random, find the probability of an event that the card drawn bears, a prime number
A bag contains 5 white balls and some blue balls. If the probability of drawing a blue ball is double that of a white ball, determine the number of blue balls in the bag
A bag contains 8 red and some blue balls. One ball is drawn at random from the bag. If ratio of probability of getting red ball and blue ball is 2:5, then find the number of blue balls.
Let E be an event and P(E) = `6/7`, then find the value of P(not E).
The probability that a relation R from {x, y} to {x, y} is both symmetric and transitive, is equal to ______.
If six students, including two particular students A and B, stand in a row, then the probability that A and B are separated with one student in between them is ______.
From a group of 10 men and 5 women, four member committees are to be formed each of which must contain at least one woman. Then the probability for these committees to have more women than men is ______.
A and B are events such that `P(A ∪ B)= 3/4`, `P(A ∩ B) = 1/4`, `P(overlineA) = 2/3` then `P(overlineA ∩ B)` is ______.
One coin and a die are thrown simultaneously. Find the probability of the following event:
Event B: To get a tail and an odd number.
