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..
