Question
A group consists of 11 boys and 9 girls. In how many
ways can 7 boys and 5 girls be selected from the group?Solution
Required number of ways = 11 C 7 × 9 C 5
= (11! / (7! × 4!)) × (9! / (5! × 4!))
= 330 × 126 = 41,580
More Permutation and combination Questions
11Â Â Â 36Â Â Â Â 112Â Â Â Â 336Â Â Â Â 1011Â Â Â Â 3036
Find the wrong number in the given number series.
12, 13, 68, 29, 220, 51
12, 14, 18, 26, 38, 64
11, 20, 38, 65, 99, 146
210, 140, 105, 84, 70, 63, 52.5Â
8Â Â Â Â Â 5Â Â Â Â Â Â 6.5Â Â Â Â Â 11.75Â Â Â Â Â 26Â Â Â Â Â 65
...In each of the following, one term is wrong. Find the WRONG term.
2, 6, 18, 54, 108, 486
147Â Â 490Â Â 707Â Â Â 831Â Â Â Â 895Â Â Â 930
18, 27, 38, 56, 66, 83
7, 16, 33, 74, 153, 312
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