Twenty tickets are marked with the numbers 1, | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The total number of ways to draw $3$ tickets out of $20$ is given by $^{20}C_3 = \frac{20 	imes 19 	imes 18}{3 	imes 2 	imes 1} = 1140$. We wa

Vedclass · Accepted Answer

$\frac{3}{190}$

Vedclass · Answer

(A) The total number of ways to draw $3$ tickets out of $20$ is given by $^{20}C_3 = \frac{20 	imes 19 	imes 18}{3 	imes 2 	imes 1} = 1140$. We want to find the probability that the tickets marked $7$ and $11$ are included in the selection. If $7$ and $11$ are already chosen,we only need to choose $1$ more ticket from the remaining $18$ tickets $(20 - 2 = 18)$. The number of ways to choose this $3^{rd}$ ticket is $^{18}C_1 = 18$. Therefore,the required probability is $\frac{18}{1140} = \frac{18}{20 	imes 19 	imes 18 / 6} = \frac{18}{1140} = \frac{3}{190}$.

Twenty tickets are marked with the numbers $1, 2, \dots, 20$. If three tickets are drawn at random,what is the probability that the tickets marked $7$ and $11$ are among them?

Similar Questions

$3$ bulbs are drawn at random from a lot of $50$ bulbs,$5$ of which are defective. Find the probability of the event that all $3$ bulbs are non-defective (drawn without replacement).

$A$ bag contains $5$ red and $4$ green balls. If four balls are drawn at random,what is the probability that two balls are red and two balls are green?

Two cards are drawn without replacement from a well-shuffled pack. Find the probability that one of them is an ace of hearts.

Two cards are drawn from a pack of $52$ cards. What is the probability that at least one of the cards drawn is an ace?

In a certain lottery,$10,000$ tickets are sold and $10$ equal prizes are awarded. What is the probability of not getting a prize if you buy $10$ tickets?

Vedclass Test Series

Exam Paper Generator

Online Exam Module