Cost is expressed by the formula tb^4. If b is doubled, the new cost R is what percent of the original cost?	Options
A) R=200  B) R=600  C) R=800  D) R=1600  E) R=50
Original Cost C1=t1*b1^4   New Cost C2= t2*b2^4....only b is doubled so t2=t1 and b2=2b1   C2=t2*(2b1)^4   =16(t1*b1^4)   =16C1   16 times C1=&gt;1600% of C1   Ans R=1600=1600
<result>D</result>
Cost is expressed by the formula tb^4. If b is doubled, the new cost R is what percent of the original cost?