<p>pg 409 #7
Dwyane has a newspaper route for which he collects k dollars a day. From this amount he pays out k/3 per day for the cost of the papers and saves the rest of the money. in terms of k how many days will it take dwyane to save $1,000</p>
<p>answer is 1,500/k</p>
<p>where do you get the 1500 from?</p>
<p>and pg 412 # 18
answer is 18 but ..........i have no clue how to get it</p>
<p>I think your questions are addressed in this thread:</p>
<p><a href=“http://talk.collegeconfidential.com/sat-preparation/339734-consolidated-list-blue-book-math-solutions-3rd-ed.html[/url]”>http://talk.collegeconfidential.com/sat-preparation/339734-consolidated-list-blue-book-math-solutions-3rd-ed.html</a></p>
<p>oh haha thanks!</p>
<p>The easiest way to solve this kind of problems</p>
<p>Assume that he earns 21 $ a day,so k = 21 .He pays 1/3 of 21$ for the cost of the newspapers ,so his daily earnings are 21-7 = 14 $.If he makes 14 a day ,how many days does he need to make 1000$ ? Of course ,1000/14 = 71.429 days
Try each answer choice starting with C (I dont know the answer choices because i burnt my blue book) ,but in your case 1500/k = 1500/21 = 71.429 :} (you have assumed that k=21) Basically,you solve the problem and try each answer</p>
<p>Now i will explain you the pure algebraic way:
He earns k $ a day,but spends 1/3 of k for the cost of the newspapers ==> he makes 2/3 k $ per day .But he needs 1000$ so 1000/2k/3 = 1000x3/2k =3000/2k = 1500/k ;}
That one was easy,but when you have sth like ''how many d dollars one needs to be b bananas that cost c cents ,you `d better plug in</p>