Answers

2014-07-07T15:59:33+05:30
N ( n + 1 ) / 2
= 9 ( 9 + 1 ) / 2
= 9 X 10 / 2
= 9 X 5
= 45
So the answer is 5.
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2014-07-07T16:07:34+05:30
1 + 2+3+4+5+6 +7+8+9=45
hence 9 lines will be reqired
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