Advertisements
Advertisements
प्रश्न
A bag contains, white, black and red balls only. A ball is drawn at random from the bag.If the probability of getting a white ball is 3/10 and that of a black ball is 2/5 then find the
probability of getting a red ball. If the bag contains 20 black balls, then find the total number of balls in the bag.
उत्तर
n(total balls in the bag) = x
`"P(getting a black ball)" =2/5=20/50="number of black balls"/"total number of balls"`
Number of black balls in the bag =20
Total number of balls = 50
`"P(getting a white ball)" =3/10=15/50="number of white balls"/"total number of balls"`
Number of white balls in the bag = 15
Number of red ball
= Total number of ball – (Number of black ball + Number of white ball)
= 50 – (20 + 15)
= 50 – 35
= 15
Total number of balls in the bag = 15.
APPEARS IN
संबंधित प्रश्न
There are three boys and two girls. A committee of two is to be formed. Find the probability of the following events:
Event A: The committee contains at least one girl
Event B: The committee contains one boy and one girl
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 multiple of 5.
A box contains cards bearing numbers from 6 to 70. If one card is drawn at random from the box, find the probability that it bears
(i) a one digit number.
(ii) a number divisible by 5.
(iii) an odd number less than 30.
(iv) a composite number between 50 and 70.
Choose the correct alternative answer for the following question.
There are 40 cards in a bag. Each bears a number from 1 to 40. One card is drawn at random. What is the probability that the card bears a number which is a multiple of 5 ?
Solve any two of the following.
If two coins are tossed simultaneously, find the probability of getting a head on both the coins.
All kings and queens are removed from a pack of 52 cards. The remaining cards are well shuffled and then a card is randomly drawn from it. Find the probability that this card is a black card.
The probability of an impossible event is
In a lottery there are 10 prizes and 25 blanks. What is the probability of getting a prize?
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 not green.
Two different dice are tossed together. Find the probability that the number on each die is even.
Two different dice are tossed together. Find the probability that the sum of the numbers appearing on the two dice is 5.
A box contains 80 discs, which are numbered from 1 to 80. If one disc is drawn at random from the box, find the probability that it bears a perfect square number.
A piggy bank contains hundred 50 p coins, seventy ₹1 coin, fifty ₹2 coins and thirty ₹5 coins. If it is equally likely that one of the coins will fall out when the bank is turned upside down, what is the probability that the coin will be a 50 p or a ₹2 coin?
A coin is tossed twice. Find the probability of getting: exactly one head
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.
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 not a red ball.
Two coins are tossed together. Find the probability of getting: no head
A coin is tossed once. Find the probability of getting a head
There are 1000 sealed envelopes in a box, 10 of them contain a cash prize of Rs 100 each, 100 of them contain a cash prize of Rs 50 each and 200 of them contain a cash prize of Rs 10 each and rest do not contain any cash prize. If they are well shuffled and an envelope is picked up out, what is the probability that it contains no cash prize?
At a Birthday Party, the children spin a wheel to get a gift. Find the probability of any toy except a chocolate
