I'm looking at a 2010 SAT prep book and one of the practice questions is as follows: 17. A dress is selling for $100 after a 20 percent discount. What was the original selling price? (A) $200 (B) $125 (C) $120 (D) $80 (E) $75 The obvious answer to me is C because it is 20 percent more. But no the book says that the answer is B. How can this be? B is 125, 25% more than the discount price.
I'm sorry but I don't understand, it's like inorder to solve the problem you have to already know the answer. The question is asking for 20% more than 100 which in my book is 120.
You are going to do so poorly on the math section. 80 100 -- = -- 100 x You cross multiply. 80 times x, 100 times 100. 80x=10,000 10,000/80=125
Heres teh equation. x= unknown original price x(.80)=$100 You multiply by .80 because 20% is being taken off, or in other words ure paying 80% of the full price. 100/.80 = 125$
It helps me to think about it as a fraction, rather then a percent. So we know that 20% is equal to 1/5. If you answered C, the discount would actually be 1/6 b/c 6*20=120. The answer is B or 125 b/c 5*25=125, therefore 20% (or 1/5) of 125 is 25. B is the correct response. I hope this helps, the questions can be tricky.
The question isn't asking you to take 20% of 100, it's asking you what you would need to take 20% from to get 100.
That is the slowest way. Considering you have roughly 30 seconds for each question, time is far too important for slow methods like that.
So you're saying, even if you didn't know how to do it any other way, it would take you more than 30 seconds to crunch out 2 equations, considering you should be able to eliminate A, D, and E almost instantaneously?
Grasscity > Everything Divide by zero my friend. EDIT: I actually looked at the problem and realized instantly it was B without seeing the options. Very simple problem IMO. I've taken the SAT's before and did ok on the math section but I'm actually retaking the SAT's just to bump up what I can tomorrow morning at 7:45.