Question

A limousine service determines that its per-mile cost is $.36 and that it incurs $48 in miscellaneous expenses for each reservation.The service charges $3.56 per mile. What number of miles represents the break-even point?

Answer 1

2)

the limousine charges 3.56 per mile driven, so, their income from the sales, or revenue is say... if they drive "m" miles, then is 3.56*m or 3.56m.

now, their costs, how much does it cost to have the limousine up and rolling and a chaffeur and other, well, it boils down to $48 for each reservation, and it costs 36 cents or $0.36 per mile driven, so, if they drive  for "m" miles, then the cost for that will be 0.36*m or 0.36m.  So the total cost is 48 + 0.36m

when is the break-even point?

the break-even point is when... well, you break-even, when the income or sales is the same as the costs, so, you're not really losing any money, you're getting as much as you're spending, but you're not making any surplus or profit either.  That happens when the Revenue = Costs.

$\bf \stackrel{revenue}{3.56m}=\stackrel{costs}{48+0.36m}\implies 3.56m-0.36m=48\implies 3.2m=48 \\\\\\ m=\cfrac{48}{3.2}\implies m=\stackrel{miles}{15}$

3)

the costs for the grower for planting and caring for a tree is 18.53, so if he plants say "t" trees, then the costs will be 18.53*t or 18.53t.

there's a fixed costs, overhead, for managing the farm, workers, cashiers, forklifts and so on, of $600.

so the total costs is then, 18.53t + 600.

now, he plans to charge for each tree 65 bucks, so if sells "t" trees, the Revenue is 65*t or 65t.

again, what's the break-even point? well Revenue = Costs

$\bf \stackrel{revenue}{65t}=\stackrel{costs}{18.53t+600}\implies 65t-18.53t=600\implies 46.47t=600 \\\\\\ t=\cfrac{600}{46.47}\implies t\approx \stackrel{trees}{12.91}$

so, the break-even point is at 12.91 trees, or 12 trees and 0.91 of another, I guess you'll just have to chop off a few branches to make it 0.91, but anyhow, if we go up to say 13 trees, the break-even point is passed and he's on the black ink, he's making profit.

so, he'll start making profit after the 12th tree sold.

4)

is the same thing more or less.

costs is $7000 in overhead, plus 24.5 for one scooter, if he makes "s" scooters, then the costs are 24.5s, so total costs is 7000 + 24.5s.

revenue is the price times quantity, if the quantity is "s" and the price is 36.75, then the revenue is 36.75s.

when he doesn't lose money?  well, is the same break-even point, not making profit, but not losing money either.

$\bf \stackrel{revenue}{36.75s}=\stackrel{costs}{7000+24.5s}\implies 36.75s-24.5s=7000 \\\\\\ 12.25s=7000\implies s=\cfrac{7000}{12.25}\implies s\approx \stackrel{scooters}{571.43}$

so, the break-even point is at 571.43 scooters, so using whole numbers wil just be 571 scooters then, well, you can't have 0.43 unless you're going to saw off the scooter, in which case you won't sell it anyway.