Probability Question 4
Question 4 - 2024 (27 Jan Shift 2)
An urn contains 6 white and 9 black balls. Two successive draws of 4 balls are made without replacement. The probability, that the first draw gives all white balls and the second draw gives all black balls, is :
(1) $\frac{5}{256}$
(2) $\frac{5}{715}$
(3) $\frac{3}{715}$
(4) $\frac{3}{256}$
Show Answer
Answer (3)
Solution
$\frac{{ }^{6} \mathrm{C}{4}}{{ }^{15} \mathrm{C}{4}} \times \frac{{ }^{9} \mathrm{C}{4}}{{ }^{11} \mathrm{C}{4}}=\frac{3}{715}$
Hence option (3) is correct.
