# Probability-Important Questions

1.   A bag contains 9 black and 12 white balls. One ball is drawn at random. What is the probability that the ball drawn is black?
2.   Find the probability that a number selected from the numbers 1 to 25 which is not a prime number when each of the given number is equally likely to be selected.
3.   A bag contains 10 red, 5 blue and 7 green balls. A ball is drawn at random. Find the probability of this ball being not a blue ball.
4.   Two dice are thrown at the same time and the product of numbers appearing on them is noted. Find the probability that the product is less than 9.
5.   Cards, marked with numbers 5 to 50, are placed in a box and mixed throughly. A card is drawn from teh box at random. Find the probability that the number on the taken out card is:
(i) a prime number less than 10.
(ii) a number which is a perfect square.
6.   Two dice are thrown simultaneously. What is teh probability that
(i) 5 will not come up on either of them?
(ii) 5 will come up on at least one?
(iii) 5 will come up at both dice?
7.   From a well suffled pack of playing cards, black jackes, black kings and black aces are removed. A card is then drawn from the pack. Find the probability of getting.
(i) a red card                        (ii) not a diamond card.
8.   A bag contains cards which are numbered from 2 to 90. A card is drawn at random from the bag. Find the probability that it bears.
(i) a two-digit number                                        (ii) a number which is a perfect square.
9.   Cards numbered 1 to 30 are put in a bag. A card is drawn at random from this bag. Find the probability that the number on the drawn card is:
(i) not divisible by 3.                                (ii) a prime number greater than 7.
(iii) not a perfect square number.
10.   Two different dice are tossed together. Find the probability:
(i) That the numbers on either die is even.
(ii) That the sum of numbers appearing on the two dice is 5.

### Comments

1. Is that possible ncert questions answer.

2. Contain is nice if possible give answer of que. 9

3. Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur or how likely it is that a proposition is true. Probability is a number between 0 and 1, where, roughly speaking, 0 indicates impossibility, and 1 indicates certainty. To learn mathematics your basic concepts should be clear. Maths is the only subject that you can learn by practicing again and again. Some of the students take the help of Online Tuition to get good marks.