Question
15 defective pens are accidentally mixed with 115
good ones. It is not possible to just look at a pen and tell whether or not it is defective. One pen is taken out at random from this lot. Determine the probability that the pen is taken out is a good one.Solution
Numbers of pens = Numbers of defective pens + Numbers of good pens
∴ Total number of pens = 115 + 15 = 130 pens
P(E) = (Number of favourable outcomes) / (Total number of outcomes)
P(picking a good pen) = 115/130 = 23/26 = 0.884
More Probability Questions
What will come in place of the question mark (?) in the following series?
1528, 1416, 1204, ?, 480, -32
143 Â Â Â Â 119Â Â Â Â 107Â Â Â Â 101Â Â Â Â Â 98Â Â Â Â ?
96 89 ? 90 94 91
...What value should come in the place of (?) in the following number series?
19, 235, 260, 324, 333, ?
What will come in place of the question mark (?) in the following series?
305...
In each of the following number series, one term is missing. Find the missing term.
3, 5, 20, 24, 144, 150, ?
1029, 1030, 1039, 1064, ?, 1194
75, 80, 95, ?, 155, 200
What will come in place of the question mark (?) in the following series?
1515, 184, ?, 455, 967, 624
7 29 61 ? 211 349
...
