Should the answer be A?
5(r+t) 5r+t
5r+5t 5r +t
5t t (subtract 5r)
5 1 (divide by t)
5>1

You're absolutely right.
I have edited my response accordingly.

Cheers,
Brent

There's a slight error in your solution.
When using matching operations, we must be sure to avoid multiplying or dividing a quantity by a negative number.
In your solution, you divided both quantities by t. However, since we don't know whether t is positive or negative, we must avoid dividing the quantities by t.

Let's take it from where you got to:
Quantity A: 5t
Quantity B: t

Notice that, if t = 0, then the two quantities are equal.
If t = 1, then Quantity A is greater
If t = -1, then Quantity B is greater
So, the correct answer must be D.

Cheers,
Brent

My Answer is D

Observe that 5r is the same, but we don't know the sign of t -> D

Case 1: t=0
In this case, quantity A \(= 5(r+0) = 5r\) and quantity B \(= 5r+0 = 5r\), so the two quantities are equal.
Eliminate A and B.

Case 2: t=1
In this case, quantity A \(= 5(r+1) = 5r + 5\) and quantity B \(= 5r + 1\), so the two quantities are NOT equal.
Eliminate C.

A B
5r + 5t 5r + t
5r removed from both sides
5t> t so A

However I have a question --> what if T is ZERO?
then 0 = 0 and answer would be D

See the explanation atop your question provided by GMATGuruNY.

If t=0 the answer is C.

If t=1 the two quantities are different.

So two conflict answers.

D is the right answer, therefore.

See for a proper strategy https://gre.myprepclub.com/forum/quantitat ... 10440.html

Regards

I picked D

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