Arithmetic Ability
 Probability

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Q.

A bag contains 6 white and 4 black balls .2 balls are drawn at random. Find the probability that they are of same colour.

View Answer

Correct choice: B

Explanation:

Let S be the sample space Then n(S) = no of ways of drawing 2 balls out of (6+4) =10C2 10 =10*92*1 =45 Let E = event of getting both balls of same colour Then,n(E) = no of ways (2 balls out of six) or (2 balls out of 4) =6C2+4C2 = 6*52*1+4*32*1 = 15+6 = 21 Therefore, P(E) = n(E)/n(S) = 21/45 = 7/15
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