A box contains 15 black and 20 white balls. W | vedclass

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

Question

(A) Total number of balls $= 15 + 20 = 35$.Total number of ways to select $2$ balls from $35$ is given by ${}^{35}C_{2} = \frac{35 	imes 34}{2 	imes

Vedclass · Accepted Answer

$\frac{38}{119}$

Vedclass · Answer

(A) Total number of balls $= 15 + 20 = 35$.Total number of ways to select $2$ balls from $35$ is given by ${}^{35}C_{2} = \frac{35 	imes 34}{2 	imes 1} = 35 	imes 17 = 595$.Number of ways to select $2$ white balls from $20$ white balls is given by ${}^{20}C_{2} = \frac{20 	imes 19}{2 	imes 1} = 10 	imes 19 = 190$.The probability of selecting both white balls is $P = \frac{{}^{20}C_{2}}{{}^{35}C_{2}} = \frac{190}{595}$.Dividing both numerator and denominator by $5$,we get $P = \frac{38}{119}$.

$A$ box contains $15$ black and $20$ white balls. What is the probability that when $2$ balls are selected,both are white?

Similar Questions

$A$ box contains $15$ black and $20$ white balls. What is the probability that when $2$ balls are selected,at most one is white?

$4$ coins are tossed once. Find the probability of getting exactly $2$ tails.

There are four machines,and it is known that exactly two of them are faulty. They are tested one by one in a random order until both faulty machines are identified. The probability that only two tests are needed is

When two dice are rolled,what is the probability that the sum of the numbers appearing is $\leq 10$?

For two events $A$ and $B$,if $P(A) = P(A|B) = \frac{1}{4}$ and $P(B|A) = \frac{1}{2}$,then

Vedclass Test Series

Exam Paper Generator

Online Exam Module