Question

One bag contains 5 white and 3 black balls and an other contains 4 white, 5 red balls. Two balls are drawn from one of them choosing at random.The probability that they are of different colours is

• A. $\frac{15}{56}$
• B. $\frac{5}{18}$
• C. $\frac{275}{504}$
• D. $\frac{275}{624}$

Answer 1

Answer: (C)

$\frac{275}{504}$

$P=\frac{1}{2}[\frac{C(3,1)\ast C(5,1)}{C(8,2)}+\frac{C(4,1)\ast C(5,1)}{C(9,2)}]=\frac{275}{504}$