Question
A bag contains 6 red, 4 green and 5 blue balls. Two
balls are drawn at random without replacement. What is the probability that both balls are of different colours?Solution
ATQ, Total balls = 6 + 4 + 5 = 15 Total ways to choose 2 = C(15,2) = 105 Same-colour pairs: Red: C(6,2) = 15 Green: C(4,2) = 6 Blue: C(5,2) = 10 Total same-colour = 15 + 6 + 10 = 31 Different-colour = 105 – 31 = 74 Probability = 74/105.
75    196    52    221    ?    250
-3 -10 -40 -185 -905 -4500
-4 a b c d e
Find the value of d.
...12 23 65 ? 1239 7409
...A restaurant has a special offer where a family meal costs ₹1,200 for 4 people. If a family of 6 orders this meal and then orders 2 additional family ...
In the question, three series I, II and III are given. Find the value of x, y and z to establish the correct relation among them and choose the correct...
22   39    58    81   ?      141
6   55   91   116   132    ?  . Â
13, 14, 18, 27, 43, ?
Which of the following numbers will replace the question mark (?) in the given series?
69, 70, 74, 83, ?, 124
21, 63, 315, ?, 19845, 218295
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