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Source: — Problem Solving |

by Suyog » Fri Nov 30, 2007 10:42 am
x(2) = 2(x(1)) -1 = 2(3) -1 = 5

As per the series...

x(1) = 2^1 + 1
x(2) = 2^2 + 1 and so on

so,
x(19) = 2^19 + 1 and
x(20) = 2^20 + 1

x(20) - x(19) = (2^20 + 1) - (2^19 + 1)
= 2^20 + 1 - 2^19 - 1
= 2^20 - 2^19
= 2^19

Ans A
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by samirpandeyit62 » Wed Dec 05, 2007 7:58 am
As per the series...

x(1) = 2^1 + 1
x(2) = 2^2 + 1 and so on

&

x(20) - x(19)

= 2x(19 ) - 1 - x(19) = x(19) -1

so reqd val is 2^19 -1 + 1 = 2^19
Regards
Samir
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