Question
From 10 musicians and 5 singers, a band of 8 members is to
be formed. In how many ways can the band be formed such that there are at least 6 musicians?Solution
Case I: 6 musicians and 2 singers
Number of ways = 10C6 × 5C2 = 210 × 10 = 2100 ways
Case II: 7 musicians and 1 singer
Number of ways = 10C7 × 5C1 = 120 × 5 = 600 ways
Case III: 8 musicians and 0 singers
Number of ways = 10C8 × 5C0 = 45 × 1 = 45 ways
Total number of ways = 2100 + 600 + 45 = 2745 ways
1001, 728, 513, 342, 217, ?
13 22 40 67 103 ?
...3  16  22  ?   98   206
25Â Â Â Â Â Â Â Â Â Â 34Â Â Â Â Â Â Â Â Â Â 61Â Â Â Â Â Â Â Â Â Â 106Â Â Â Â Â Â Â Â 169Â Â Â Â Â Â Â Â ?
...3 2 10 ? 17 16
...18 113 559 2247 6721 13451
...If 2.5 3.5 x 30 124 625
Then, x ² - 1 - 2x = ?
...64Â Â Â Â Â Â 66Â Â Â Â Â Â Â 76Â Â Â Â Â Â 126Â Â Â Â Â Â 376Â Â Â Â Â Â Â ?
...To find the Next number in the given series.
342 510 726 996 1326 ?
...8, 9, 15, ?,82.5, 250.50
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