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
Answer:
625
Step-by-step explanation:
Answer:
$60, $90
Step-by-step explanation:
Amount paid when 50% off
=$ 120 - 50/100 * 120 = $ 120 - $60 = $60
Amount paid when 25% off
=$ 120 - 25/100 * 120 = $ 120 - $30 = $90
