Curioustab

Home » Aptitude » Probability

Out of first 20 natural numbers, one number is selected at random. The probability that it is either an even number or a prime number is ?

16/19
1
3/2
17/20

Correct Answer: 17/20

Explanation:

n(S) = 20
n(Even no) = 10 = n(E)
n(Prime no) = 8 = n(P)
P(E U P) = 10/20 + 8/20 - 1/20 = 17/20

← Previous Question Next Question→

More Questions from Probability

A brother and a sister appear for an interview against two vacant posts in an office. The probability of the brother’s selection is 1/5 and that of the sister’s selection is 1/3. What is the probability that only one of them is selected?
A bag contains 7 green and 5 black balls. Three balls are drawn one after the other. The probability of all three balls being green, if the balls drawn are not replaced will be:
One card is drawn from a pack of 52 cards, each of the 52 cards being equally likely to be drawn find the probability the card drawn is red.
A bag contains 8 red and 4 green balls. Find the probability that two balls are red and one ball is green when three balls are drawn at random.
If P(A)=4/9;then the odd against the event A is:
If a card is drawn at random from a pack of 52 cards,what is the chance of getting a spade or ace?
One lady has 2 children, one of her child is boy, what is the probability of having both are boys ?
If two dice are thrown together, the probability of getting an even number on one die and an odd number on the other is ?
In a party there are 5 couples. Out of them 5 people are chosen at random. Find the probability that there are at the least two couples ?
In a simultaneous throw of two dice, what is the probability of getting a doublet ?

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion