The answer is A because it is
Answer:
the fourth one should be the answer
Answer:
6 knots
Step-by-step explanation:
Let the speed be v knots
then time taken to cover 500 M = 500 / v hrs
fuel consumption /hr = 216 + 0.5v^3
let F be the fuel consumption for trip
= [500/v][216 + 0.5v^3]
= 500[216/v + 0.5v^2]
dF/dv = 500[ - 216/v^2 + v]
d^2F/d^2v = 500[432/v^3 + 1] , i.e. +ve
so setting dF/dv will give a minima
500[ -216/v^2 + v] = 0
or v = 216/v^2
or v^3 = 216
solving, we get v = [216]^(1/3) = 6 knots
"The number 39 is equal to"
39=
"thirteen subtracted from an unknown number"
r-13
Putting it together you have:
39=r-13
Do the equation . Pi(r)^2
Radius is 13.
Pi equals technically 3.14
So theoretically ,
3.14(13)^2= 530.929158457
=531
