A shoe cobbler charges n dollars to repair a single pair of loafers.

Question

A shoe cobbler charges n dollars to repair a single pair of loafers. Tomorrow, he intends to earn 240 dollars repairing loafers. If he were to reduce his fee per pair by 20 dollars, he would have to repair an additional pair of the loafers to ear the same amount of revenue. How many pair of loafers does he intend to repair tomorrow?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

240/n = 240/(n - 20) - 1

n = 80

240/n = 240/80 = 3.

Answer: C.

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Bunuel · Accepted Answer

A shoe cobbler charges n dollars to repair a single pair of loafers. Tomorrow, he intends to earn 240 dollars repairing loafers. If he were to reduce his fee per pair by 20 dollars, he would have to repair an additional pair of the loafers to ear the same amount of revenue. How many pair of loafers does he intend to repair tomorrow?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

240/n = 240/(n - 20) - 1

n = 80

240/n = 240/80 = 3.

Answer: C.

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

240/n = 240/(n - 20) - 1

n = 80

240/n = 240/80 = 3.

Answer: C.

jjack0310 · Answer

Wouldn't the answer actually be D - 4?

The question is asking for how many pair of loafers does he intend to repair tomorrow?

This is (x + 1) (because he would have to repair an additional pair)
So shouldn't the answer be (x + 1 = 3 + 1 = 4 = D ??)

Thanks for the help

Bunuel · Answer

We are told that the cobbler charges n dollars to repair a pair of shoes. Then we are told that IF he charged n-20 dollars he would have to repair an additional pair. Notice that we are not told that he WILL charge n-20 dollars, just IF.

Hope it's clear.

jjack0310 · Answer

So technically, they have given the future scenario for the cobbler just so we can solve the problem. 
I mean without that specific sentence we would have too many unknowns.

I think I was over thinking the problem. 
Thanks,

Bunuel · Answer

Correct. Only that "n-20 dollars" case is not a future scenario it's a hypothetical scenario.

Skag55 · Answer

The loafer charges n per pair, and he is intending to make 240 from x pairs:

240 = x * n

If he wants to reduce the price by 20 (n - 20) he needs to repair 1 more ( x + 1)

240 = (n-20)(x+1)
xn = (n-20)(x+1)
xn = xn + n - 20x -20
n - 20x = 20......

what am I doing wrong?

Skag55 · Answer

Should it be  +1  ?

Bunuel · Answer

This is not a best way to solve the problem but you could still get the correct answer:
From 240=xn --> x=240/n --> substitute: n - 20*240/n= 20 --> solve: n=80 --> 240/80=3.

Bunuel · Answer

Let me ask you a question: which is greater 240/n or 240/(n-20)?

chetan2u · Answer

Hi,
 Since you have asked without algebric calculations, one method which will depend on the INFO we INFER from Q.. 
 1) since price per loafer is reduced by 20, the earlier price >20..
2) Also 240 is teh total cost, the OLD and REDUCED price must be factor of 240..
3) From th e above two points, the OLD and REDUCED price must be one of 24,30,40,48,60,80,120,240..
4) We have to choose two prices amongst the value above which have a difference of 20..
5) so our ansewr is either 40 and 60 or 60 and 80..
6) if its 40 and 60 .. he earlier purchased 240/60=4 and now can purchase 240/40=6..
the difference is 2, but as per Q its 1..
2) if its 80 and 60 .. he earlier purchased 240/80=3 and now can purchase 240/60=4..
the difference is 1.. this is our answer

This was to explain the procedure ..
 but a straight requirement to find the CORRECT answer is..
two pair of factors of 240 equalling 240, with change in one of them by 20 leading to lowering the other factot by 1.. 
240 =80*3
240=60*4..
so this is the answer
he would do 3..

KarishmaB · Answer

The options and numbers in the question are easy enough to merit a simple plug in. 
He cannot intend to repair only 1 or 2 pairs tomorrow because a reduction of just $20 will not amount to cost of repairing one pair of loafers. 
So try plugging in 3. If he repairs 3 pairs tomorrow at a price of $240/3 = $80 per pair, and if instead he brings down the cost to $60, he will need to repair 240/60 = 4 pairs of loafers. This works.

Answer (C)

bumpbot · Answer

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A shoe cobbler charges n dollars to repair a single pair of loafers.

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A shoe cobbler charges n dollars to repair a single pair of loafers.

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