Question
A bag has x blue balls and 4 yellow balls. If the
probability of picking a blue ball is 3/5, find the probability that two balls drawn at once are of different colours.Solution
Total number of balls = x + 4 So, x / (x + 4) = 3/5 ⇒ 5x = 3x + 12 ⇒ 2x = 12 ⇒ x = 6 Desired Probability = (⁶C₁ × ⁴C₁) / ¹⁰C₂ = (6 × 4) / (10 × 9 / 2) = 24 / 45 = 8/15
More Probability Questions
- Find the wrong number in the given number series.
10, 14, 23, 48, 99, 218 119, 200, 137, 182, 156, 164
43, 42, 41, 39, 33, 10
2, 10, 30, 64, 130, 222
92, 88, 79, 63, 40
182, 240, 306, 380, 462, 558
109 106 101 94 86 74
...32, 16, 24, 60, 207, 945
Find the wrong number in the given number series.
1900, 1171, 669, 316, 100, - 25
6, 24, 125, 720, 5040, 40320
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