Help please!! The maximum value of total revenue correspond to a price of

9514 1404 393

  d.  $30

Step-by-step explanation:

When price and demand are linearly related like this, revenue is a quadratic function. Its maximum will be halfway between the prices that give a revenue of 0. Those prices are $60 (where demand is 0) and $0 (where demand is irrelevant). The halfway point is ($60 +0)/2 = $30.

As a check, you can figure revenue for some nearby points.

  at $30, revenue is ($30)(15) = $450

  at $24, revenue is ($24)(18) = $432

  at $36, revenue is ($36)(12) = $432

This confirms revenue is maximized at a price of $30.

b. t=-25h+3

step-by-step explanation:

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.