Question
Ten tickets numbered 1 to 15 are placed in a box, mixed
up thoroughly and then one ticket is drawn randomly. If it is known that the number on the drawn ticket is more than 3, what is the probability that it is an even number?Solution
Let A be the event ‘the number on the ticket drawn is even’ and B be the event ‘the number on the ticket drawn is greater than 3’. We have to find P(A|B). Now, the sample space of the experiment is S = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15} Then A = {2, 4, 6, 8, 10, 12, 14}, B = {4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15} and A ∩ B = {4, 6, 8, 10, 12, 14} Also P(A) = 7/15, P(B) = 12/15 and P(A ∩ B) = 6/15 Then P(A|B) = P(A ∩ B)/P(B) = (6/15)/(12/15) = 1/2
What will come in place of (?) question mark in the given number series.
16, 24, 51, 115, 240, ?
Find the missing number in the given number series.
512, 128, 32, 8, ?, 171, 79, 88, 152, ?, 393
15, 31, 67, 131, ?, 375
1, 26, 75, 156, 277, ?
7 29 61 ? 211 349
...18   29   16   31   ?   33
72, 82, 62, 102, 22, ?
?, 15, 45, 225, 1575, 14175
166    156    136   ?     66    16
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