Giselle79 Posted April 10, 2012 Share Posted April 10, 2012 During a sale, a store sells 20 percent of its remaining stock each day, without replenishment. After 4 days, what fraction of its original stock has it sold? A- 1/625 B- 256/625 C- 61/125 D- 64/125 E- 369/625 How is it E correct answer: please explain in a simple way. thanks Quote Link to comment Share on other sites More sharing options...
thepillow Posted August 28, 2012 Share Posted August 28, 2012 Hi Giselle, Since your post is titled "picking numbers", I'll use that approach: Let's say that the store starts with 10,000 items. Day 1: sell .20(1000) = 2000, 8000 left over Day 2: sell .2(800) = 1600, 6400 left over Day 3: sell .2(640) = 1280, 5120 left over Day 4: sell .2(512) = 1024, 4096 left over Ok, so this means out of the original 10,000, there are only 4096 left. So 10,000 - 4096 = 5904 were sold during the 4 days. The fraction of the total = 5904/10000, which can be reduced to 369/625. Hope that helps! Quote Link to comment Share on other sites More sharing options...
GMAT Prepster Posted September 20, 2012 Share Posted September 20, 2012 I would that you would do 1 - (4/5)^4 which is 1 - 256/625, leaving E as the answer. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.