I think it's 720
Have a GREAT day!
Answer:
Option A. 
Step-by-step explanation:
we know that
The lateral area of a cone is equal to

we have


substitute and solve for l (slant height)

simplify


To calculate the remaining caffeine, we use the radioactive decay formula which is expressed as An = Aoe^-kt where An is the amount left after t time, Ao is the initial amount and k is a constant we can calculate from the half-life information. We do as follows:
at half-life,
ln 1/2 = -k(6)
k = 0.12/hr
An = 80e^-0.12(14)
An = 15.87 mg
4 yards and 2 feet is equal 14 feet since each yard is made up of 3 feet.
1 yard = 3 feet.
So if we take 14 feet and multiply that by 3 we get 42 feet.
42/3 is equal to about 14 yards in total
So the answer is 14 yards.
No; we have
. Substituting these into the DE gives

which reduces to
, true only for
.