theGame001 wrote:
Cost is expressed by the formula tb^4. If b is doubled, the new cost is what percent
of the original cost?
(A) 200
(B) 600
(C)800
(D) 1600
(E) 50
I read the explanation in Manhattan but cant relate to it.
I worked it out this way
Assume,
t=1
b=2
Original = (1*2)^4= 16
New= (1*2*2)^4 = 256
% change= (change/Original)*100
=(240/16)*100
=1500
Where am I going wrong?
Thanks
The question asks for the relative percent b/w the new cost and the final cost, that is \(\frac{256}{16}*100\) and NOT the precent increase/decrease.
For example, initial cost=1 , final cost = 2, and the question asks what percent of the original cost is the final cost : \(\frac{2}{1}*100\) = 200%
Again, if the question asks, what is the percent increase between the final and the initial cost : \(\frac{2-1}{1}*100\) = 100%
Ahhhh, okay. Thanks, I clearly misinterpreted the question.
close
81% (01:23) correct 
