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Percentage Problem

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Percentage Problem

by lali_mew » Fri Aug 29, 2008 7:57 am
Gold depreciated at a rate of X% per year between 2000 and 2005. If 1 kg of gold costs S dollars in 2001 and T dollars in 2003, how much did it cost in 2002?
1) TS/2
2) T root(T/S)
3) T root(S)
4) T S/root(T)
5) root(ST)


OA = 5

Can somebody tell me how?
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Re: Percentage Problem

by sudhir3127 » Fri Aug 29, 2008 8:22 am
lali_mew wrote:Gold depreciated at a rate of X% per year between 2000 and 2005. If 1 kg of gold costs S dollars in 2001 and T dollars in 2003, how much did it cost in 2002?
1) TS/2
2) T root(T/S)
3) T root(S)
4) T S/root(T)
5) root(ST)


OA = 5

Can somebody tell me how?

Cosf gold in 2001 is S and it depreciates @ X%

In 2002 it will be = S- X%of S = S(1-0.01X) .......................1

Assume Y be the cost in 2002. Then,

Y-X%ofY = T
=Y(1-0.01X) = T
=Y = T/(1-0.01X) ........................................................... 2

From 1 and 2


T/(1-0.01X) = S(1-0.01X)

= (1-0.01X)^2 = T/S
therefore
1-0.01X = (T/S)^(1/2)

we know that price in 2002 is S( 1-.01X) from 1

there fore its S* sqrt T/ sqrt S
= Sqrt (TS)

hope that helps..
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