Damn, people be posting some tricky questions. This one is easy but it sucks because logically you need both. But you need to employ this general equation which I've seen in the GMAT before. Sales - expenses = gross profit. A states that GP = 1/3E. Plugging this into the equation gives you S - E = 1/3 E. Multiply both sides by three and get 3s-3e = e. Add 3e to both sides to get 3s=4e. This can be simplified to 3/4=e/s. so the ratio of expenses to sales is three to four. Plug this ratio into the equation and get 4-3=1. Therefore, A is sufficient because you can tell that the ratio is 1/4. Eliminate B,C,and E.

B says expenses were 3/4 revenue. This is saying e=3/4r. Following the same logic in one you can quickly tell that both of these are correct and that the answer is D. I don't like this only because it's tricky and it assumes you know the profit formula which isn't talked about much but can apparently show up. It's not a hard formula to remember and you should know it but just look out for tricky stuff like this.

This questions requires you to think about what profit means and the definition of Revenue and Expenses. The equation is as followed.

P = Rev - Exp

You are solving for P/Rev - and when you are solving for the value of an equation (not a variable) you should look to see if you can manipulate the equations given to get a solution.



1) Gives you the equation P = 1/3E with the principle of manipulating you can combine it with the other equation
1/3E= Rev - Exp which means that Rev=4/3 Exp. (1/3)Exp/ (1/3) Exp - the expenses factor out and therefore you can solve it. AD

2) Similarly E=3/4R so from above P= R - 3/4(r) which means P=(1/4)R [substituting] therefore (1/4)R/R - the R's factor out so you can solve it.

This is agood way to solve any algebra question that asks for hte value of an equation.