Not sure how to do this! I think it might have something to do with break-even

[elly39951]

The cost ($) of making n apple pies is given by the equation C= 1.5*n +20.

The profit from the sale of 80 apple pies is $100.

The selling price of one apple pie is:

A - $1.50

B - $1.75

C - $2.50

D - $2.75

E - $3.75

Can you please tell me how you arrive at an answer?

Thanks in advance if you can help out!

[Stick]

A very good question that has regularly popped up in the examinations! I'll try to walk you through it.



(As you should be aware, a revenue equation always goes through the origin, hence we know the relationship will be in the form y=kn, where k is a constant - in this case the revenue for one apple pie).

Tip: Remember to put your cost equation in brackets! Otherwise, you will end up with the incorrect sign to your value. So many students forget to do this and get the answer wrong despite the rest of the workings being correct.

(I have just subbed in 80 for n).









Which isn't one of the given answers. :|

[abcdqd]

guessing the +20 involved in the cost price isnt a part of the calculation of profit? if so, 100/80 = 1.25 proft per pie, so selling price = 1.5+1.25= 2.75?

[Stick]

From my previous experiences, the fixed costs are always used in this sort of calculation. :/ Perhaps this is an exception, but I don't think that should be the case. In practical terms, you would not omit any overhead costs in the calculation of profit, would you? :S

[Stick]

I think they mean this?
It must be a typographical error for the question or something.
This is the only way you can get a suitable solution from Multiple choice.

Profit = Selling price x 80 - cost to make 80
100 = 80 x k - (1.5 x 80 - 20)
Which is 100 + (120-20) = 80k
200=80k
k = 200/80
k = 20/8
k = 2.5 dollars

You've subtracted the fixed cost in the brackets by mistake here. :/

[Quantum.Mechanic]

Ah.
My mistake.
There would be no way to get the solution with that fixed cost of 20.
I should have seen the -20, which doesn't exist since fixed costs are always positive.

[Stick]

Well it seems we have yet another broken Further Maths question! These are so common in revision material that it isn't even funny. :|

[Quantum.Mechanic]

Yeah.
I guess thats true. Someone should release a Further Mathematics book with a few hundred questions that are all correct...

[taiga]

Wait for the ATARNotes book

[Jordzs]

I got the same answer as Stick up there by using a different method

[elly39951]

guessing the +20 involved in the cost price isnt a part of the calculation of profit? if so, 100/80 = 1.25 proft per pie, so selling price = 1.5+1.25= 2.75?

Um well $2.75 is the answer from the text book, so can anyone else get it? I think when I did it I kept getting B which was $2.75 a dollar off

[abcdqdxD]

$2.75 is correct

[Jordzs]

With my calculations, if that +20 wasn't at the end of it, $2.75 would most definitely work out. Not sure, keep getting 3 lol

[abcdqdxD]

With my calculations, if that +20 wasn't at the end of it, $2.75 would most definitely work out. Not sure, keep getting 3 lol

Depends whether you treat the +20 as a fixed cost or as a variable cost

[elly39951]

$2.75 is correct

How did you get this?