test series

Question

All 2 digit numbers are written in ascending order with a vertical line separating every pair of consecutive numbers. The number of these vertical line is _

Comments

SOLUTION GIVEN AS:

The pair of such numbers are
11/12; 22/23; 33/34; 44/45; 55/56; 66/67; 77/78; 88/89; 89/90 i.e 9

but i think 44 is the ans.

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@hs_yadav tell me why (1,2) and (2,3) can't be pair

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How u come upto 44?

Answer 1

First let us take smaller example let n=5

I.e 1,2,3,4,5

Now we have 4 consecutive pairs 1,2 2,3 3,4 4,5

So to separate it we require 4 vertical lines

1|2|3|4|5

Thus for n numbers we require n-1 lines so there are 90  numbers from 10-99 thus we require 89 vertical lines

Comments

*consecutive pairs and vertical lines

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Didn't get your comment

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It should be 4 *consecutive pairs

and in the last line, it will be *vertical lines