Question
A bag contains 4 violet, 2 grey and 6 black pullovers. 3
pullovers are chosen at random. What is the probability that at least 2 pullovers chosen will be violet?Solution
There will be two cases: Case I: 2 violet, 1 (grey or black) Probability = 4C2 × 8C1/ 12C3 = 12/55 Case II: all violet Probability = 4C3/12C3 = 1/55 Total probability = 12/55 + 1/55 = 13/55
More Permutation and combination Questions
4 ? 113 449 1343 2681
...14 15 34 116 460 2325
...There are three series given below which are following with the same pattern.
Series I: 21, 44, 135, 544, 2725
Series II: 14, B, C, D, E
40    42    87    266    ?     5366
3 2 10 ? 17 16
...91   93   97   100   ?   113
11, 12, 16, 25, ?, 66
1 5 36 343 ? 59049
...2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 5Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 10Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ...
59, 170, 301, 452, ?, 814
