A flashlight has 10 batteries,out of which 4 | vedclass

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

Question

(A) Total number of batteries = $10$. Number of dead batteries = $4$. We need to select $3$ batteries without replacement. The probability that the fi

Vedclass · Accepted Answer

$ \frac{1}{30} $

Vedclass · Answer

(A) Total number of batteries = $10$. Number of dead batteries = $4$. We need to select $3$ batteries without replacement. The probability that the first battery is dead = $\frac{4}{10}$. After selecting one dead battery,the remaining number of batteries is $9$ and the remaining number of dead batteries is $3$. The probability that the second battery is dead = $\frac{3}{9}$. After selecting two dead batteries,the remaining number of batteries is $8$ and the remaining number of dead batteries is $2$. The probability that the third battery is dead = $\frac{2}{8}$. Therefore,the probability that all $3$ batteries are dead = $\frac{4}{10} 	imes \frac{3}{9} 	imes \frac{2}{8} = \frac{24}{720} = \frac{1}{30}$.

$A$ flashlight has $10$ batteries,out of which $4$ are dead. If $3$ batteries are selected without replacement and tested,then the probability that all $3$ are dead is:

Similar Questions

Out of $100$ students,two sections of $40$ and $60$ are formed. If you and your friend are among the $100$ students,what is the probability that you both enter the same section (in $/33$)?

$A$ bag contains $5$ white,$7$ red,and $8$ black balls. If four balls are drawn one by one without replacement,what is the probability that all are white?

An old man forgets the last two digits of a telephone number. He dials these two digits randomly. What is the probability that he dials the correct number?

From a well-shuffled pack of $52$ cards,two cards are drawn at random. The probability that both cards are kings is:

Two numbers $b$ and $c$ are chosen at random in succession without replacement from the set $\{1, 2, 3, \ldots, 9\}$. Then the probability that $x^2 + bx + c > 0, \forall x \in R$ is

Vedclass Test Series

Exam Paper Generator

Online Exam Module