<p>1) If 10 men can survive for 24 das on 15 cans of rations, how many cans will be needed for 8 men to survive for 36 days?</p>
<p>A. 15
B. 16
C. 17
D. 18
E. 19</p>
<p>2) It takes 16 faucets 10 ours to fill 8 tubs, how long will it take 12 faucets to fill 9 tubs?</p>
<p>A. 10
B. 12
C. 13
D. 14
E. 15</p>
<p>I always have problems with this type of question. How do you solve it?! Thanks so much :)</p>
<p>Disclaimer: I'm not a math genius.</p>
<p>I got D. 18 for 1.</p>
<p>If 10 men can survive for 24 days on 15 cans. They survive on .625 cans per day. Divide that by 10 and each man needs 0.0625 cans a day.</p>
<p>Then take 0.0625 x 8 men x 36 days = 18.</p>
<p>You were right about #1.</p>
<h1>2 is E. Its solved using a similar process.</h1>
<p>^ how would you do #2? i can't get it..</p>
<p>1) (15/10/24)<em>8</em>36
2) 9/(8/16/10*12)</p>
<p>If you are having trouble with these, you just need to get the concepts right because the math itself is simple. Concepts can be tough, though, but you can think about how you do easier problems. </p>
<p>If 10 people order 3 pizzas, how much pizza can each person eat, assuming everyone eats the same amount? You are diving 3 pizzas, that's the thing you are interested in: you want pizza/person ("pizza per person") not person/pizza. What is the difference? Pizza per person is how much pizza one person has, i.e. how much a single person can eat. Person(s) per pizza is how many people one pizza has, i.e. how many people end up eating a single pizza. It's the translation between the English and the Math that's the problem, so you need to focus on that. </p>
<p>For #2, you want to get how much each faucet contributes to a tub per hour, this gets your rate -- at least how I did it. So 8 tubs is shared among 16 faucets over a period of 10 hours, 8/16/10 gets you tubs/faucet/hour. But this is just 1 faucet, you have 12. So 8/16/10*12 is what you get for 12 faucets in an hour. Muliplying this by x=#hours will give you how many tubs</p>
<p>8/16/10<em>12</em>x = 9
x = 9/(8/16/10*12) = 15.</p>
<p>For #2 I composed an equation:
so: 16f*10h=8t
(16f)(10h)/8t = 1</p>
<p>and: 12f*x hours = 9t
(12f)(x hours)/9t = 1</p>
<p>then make the equations equal each other and solve for x, which is 15.</p>
<p>@nathan: thank you so much for the equations; it rang a bell for me! but how come this method doesn't work for #1?</p>
<p>@sreis: ugh, i'm still fairly confused with the concept, but you made it much clearer. thanks!</p>
<p>EDIT: Nevermind, I think I've got it! Thanks so much, CC comes through for me once again ^__^</p>