A bookstore has a complicated, but nice discount policy. If you buy a $20 book today, you get a 2% discount on your next purchase. Buy a $15 book, and you get 1.5% discount on your next purchase.
If you buy three books that cost $10, $20 and $30, you could buy the $30 book today, the $10 book tomorrow (with a 3% discount) and the $20 book the next day and get a 1% discount. Or you could buy the $30 and $20 book today and get 5% back on your $10 purchase tomorrow.
What is the cheapest way to buy five books at $10, $20, $30, $40 and $50?
I'm posting one puzzle, riddle, math, or statistical problem a day. Try to answer each one and post your answers in the comments section. I'll post the answer the next day. Even if you have the same answer as someone else, feel free to put up your answer, too!
Friday, April 18, 2008
But is it Worth Paying the Gas to Go Back?
Labels: logic puzzle
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* I buy $20 and $30 books today.ReplyDelete
* Then I buy $40 and $50 books in
the next purchase.
* I get 2% discount on this
purchase.so I pay $88.2(90*2/100)
* Next day i buy $10 book on which
I get 5% discount. so I pay $9.5
* Total amount paid is $147.7
I believe you can save more.ReplyDelete
You put together $80 worth of books the first day and get 8% on a $70 purchase tomorrow. Or, you could put together $70 the first day and get 7% on a $80 purchase tomorrow. Both ways save you $5.60. Which means you pay a total of $144.40.