Advertisements
Advertisements
प्रश्न
Three different coins are tossed simultaneously. Find the probability of getting exactly one head.
उत्तर
Total possible outcomes of tossing three coins simultaneously are
{ TTT, TTH, THT, THH, HTT, HTH, HHT, HHH } that is 8
We have to find the probability of getting exactly one head.
Cases of exactly one head are {TTH, THT, HTT} that is 3
The probability of getting exactly on head is `3/8`.
APPEARS IN
संबंधित प्रश्न
A box contains 20 cards numbered from 1 to 20. A card is drawn at random from the box. Find the probability that the number on the drawn card is divisible by 2 or 3.
Three distinct coins are tossed together. Find the probability of getting
(i) at least 2 heads
(ii) at most 2 heads
Two dice are thrown. Find the probability of getting :
1) The sum of the numbers on their upper faces is at least 9.
2) The sum of the numbers on their upper faces is 15.
3) The number on the upper face of the second die is greater than the number on the upper face of the first die.
A bag contains cards numbered from 1 to 49. A card is drawn from the bag at random, after mixing the cards thoroughly. Find the probability that the number on the drawn card is a perfect square.
The following table shows the blood-groups of employees in a bank.
Event C is : ‘the blood-group of an employee is AB.’
| Blood - group | A | B | AB | 0 |
| No. of employees | 20 | 40 | 15 | 25 |
If an employee is chosen at random, what is the probability that his blood-group is AB ?
Fill in the following boxes and find the answer
n(S)= ______
n(C)= ______
p(C)=________=_________
A bag contains cards numbered from 1 to 49. A card is drawn from the bag at random, after mixing the card thoroughly. Find the probability that the number on the drawn card is a perfect square
In a bag there are 44 identical cards with figure of circle or square on them. There are 24 circles, of which 9 are blue and rest are green and 20 squares of which 11 are blue and rest are green. One card is drawn from the bag at random. Find the probability that it has the figure of blue circle and
A two digit number is to be formed using the digits 0, 1, 2, 3. Repetition of the digits is allowed. Find the probability that a number so formed is a prime number.
A coin is tossed once. What is the probability of getting a tail?
A bag contains 4 white balls, 5 red balls, 2 black balls and 4 green balls. A ball is drawn at random from the bag. Find the probability that it is black.
All kings, queens and aces are removed from a pack of 52 cards. The remaining cards are well-shuffled and then a card is drawn from it. Find the probability that the drawn card is a red card.
A game consists of tossing a coin 3 times and noting the outcome each time. If getting the same result in all the tosses is a success, find the probability of losing the game.
A die is thrown, find the probability of getting:
a number not greater than 4.
A bag contains 3 white, 5 black and 2 red balls, all of the same shape and size. A ball is drawn from the bag without looking into it, find the probability that the ball drawn is a black ball.
A bag contains 3 white, 5 black, and 2 red balls, all of the same shape and size. A ball is drawn from the bag without looking into it, find the probability that the ball drawn is a white ball.
In a single throw of a die, find the probability that the number:
(i) will be an even number.
(ii) will be an odd number.
(iii) will not be an even number.
Two coins are tossed together. What is the probability of getting:
(i) at least one head
(ii) both heads or both tails.
An experiment whose outcomes cannot be predicted exactly in advance is called a ______ experiment.
On throwing a dice once, the probability of occurence of an even number is `1/2`.
A card is drawn at random from a pack of well shuffled 52 playing cards. Complete the following activity to find the probability that the card drawn is:
Event A: The card drawn is an ace.
Event B: The card drawn is a spade.
Activity: 'S' is the sample space.
∴ n(S) = 52
Event A: The card drawn is an ace.
∴ n(A) = `square`
P(A) = `square` ......(formula)
∴ P(A) = `square/52`
∴ P(A) = `square/13`
Event B: The card drawn is a spade.
∴ n(B) = `square`
P(B) = `(n(B))/(n(S))`
∴ P(B) = `square/4`
