sum of 2 missing numbers of the sequence 6, ?, 20, 15, ?, 1 will be

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10 Sep 2012 sequence

sum of 2 missing numbers of the sequence
6, ?, 20, 15, ?, 1
will be

OPtion

1) 15
2) 17
3) 19
4) 20
5) 21
6) 23
7) 25
8) 27
9) 30
10) none of these

Solution

sequence is 6C1, 6C2, 6C3, 6C4, 6C5, 6C6

6/1
6*5/2*1
6*5*4/3*2*1
6*5*4*3/4*3*2*1
6*5*4*3*2/5*4*3*2*1
6*5*4*3*2*1/6*5*4*3*2*1

Correct Option: 5 Best Solution (7)