At a certain photoprocessing shop, the first standard-size print of a

Question

At a certain photoprocessing shop, the first standard-size print of a negative costs $4, and each additional print of the same negative costs $1. What is the total cost, in dollars, of y standard-size prints of each of x different negatives?

A. 4xy + (x - 1)y

B. 4xy + (y - 1)x

C. 4x + xy

D. 4x + xy - 1

E. 4x + x(y - 1)

Source: Skills Insight

A. 4xy + (x - 1)y

B. 4xy + (y - 1)x

C. 4x + xy

D. 4x + xy - 1

E. 4x + x(y - 1)

Source: Skills Insight

Bunuel · Accepted Answer

At a certain photoprocessing shop, the first standard-size print of a negative costs $4, and each additional print of the same negative costs $1. What is the total cost, in dollars, of y standard-size prints of each of x different negatives?

A. 4xy + (x - 1)y

B. 4xy + (y - 1)x

C. 4x + xy

D. 4x + xy - 1

E. 4x + x(y - 1)

Source: Skills Insight

A. 4xy + (x - 1)y

B. 4xy + (y - 1)x

C. 4x + xy

D. 4x + xy - 1

E. 4x + x(y - 1)

The first print of a negative costs $4, and  each  additional   print of the same negative costs $1.

One print of a negative costs $4;
Two prints of the negative cost $4 (for the first print) plus $1 (for the second print) = $5
Three prints of the negative cost $4 (for the first print) plus $1 (for the second print) + $1 (for the third print) = $6
...

So, the first print costs $4 and all subsequent prints of the same negative cost $1 each.

Now, y prints of a negatives will cost $4 for the first print, and $1 for each of the the remaining prints of the negative, so $1 for each of the remaining (y-1) prints. So, the total of $4*1 + $1*(y - 1). For example:

10 prints of a negatives will cost $4 for the first print, and $1 for each of the the remaining 10 -1 = 9 prints of that negative: $4*1 + $1*(10 - 1).

Now, if we have x different negatives, then to print y prints of each, we'd need x*(4 + (y - 1)) = 4x + x(y - 1). For example:

Say we have 3 different negatives and want to print 10 prints of each. 10 prints of one negative will cost 4 + (10 - 1) dollars and 10 prints of 3 different negatives will cost 3*(4 + (10 - 1)).

Answer: E.

Hope it's clear.

P.S. This is an official question, so I suggest to study it carefully.

stne · Answer

For one negative the cost for  y  prints :

4 +(y-1)1

For  x  negatives the cost for  y  prints:

=x(4 +(y-1)1)

=4x+x(y-1)

Ans E

summerindecember · Answer

Hi  stne , I don't understand the question.

Why is "(y−1)1"? Why do we need to add "(y−1)1" to "4"? Why do we need to subtract 1 from y?

pudu · Answer

the way you are explaining is amazing.....hats off you....it took hours for me to crack....but when i read your explanation i felt is is very easy .....thank you so much ...

LongTermWarrior · Answer

The wording of the question is ambiguous and may lead to confusion, I'm surprised this is an official Q.

I understood this Q as if all X negatives were different for each y as the Q states: "y standard-size prints of each of x different negatives". So if all X negatives are different, then the solution would be 4xy.

For example, if we need to print 2 standard-size prints of each of 3 different negatives, the cost would be = $4*3 + $4*3 = $4*3*2 (or 4*x*y).

The answer shown above requires an assumption that all Ys are the same.

Right?

Krunaal · Answer

y's are number of prints for each of x different negatives; the wording of question seems clear enough.

Taking your example,
Let's say if I have 3 different negatives => x = 3
I want 2 prints of each => y = 2

For 1 negative, the cost will come to => 4*(1) + 1*(2-1) = $5
For 3 negatives, the cost will come to => 3 * 5 =  $15

4x + x(y-1)  = 12 + 3(2-1) =  $15

bumpbot · Answer

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At a certain photoprocessing shop, the first standard-size print of a

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