10 Reals Help Please

<p>Hi, I am back, So if anyone is willing to help me out, please do :)</p>

<p>May 1997 Test (pg 454)</p>

<p>25.) The price for ground coffee is d dollars for 8 ounces and each ounce makes c cups od brewed coffee. In terms of c and d, what is the dollar cost of the ground coffee beans required to make 1 cup of brewed coffee
A. d/8c
B. cd/8
C. 8c/d
D. 8d/c
E. 8cd</p>

<p>November 1995 (pg 305)</p>

<p>Section 4</p>

<p>24.) There are 120 red marbles and 80 blue marbles in a bag that contains 200 marbles. If only blue marbles are added to the bag so that the probability of randomly drawing a blue marble from the bag becomes 2/3, how many blue marbles must be added to the bag?</p>

<p>Thanks!</p>

<p>BTW: (i checked studyhall already, the solution is either vague or missing)</p>

<p>25)
d=8oz
1 oz=c
so d=8c --> 1=8c/d</p>

<p>24) Probabiliy: #blue/#total, so 2/3=(80+b)/(200+b)
Cross multiply: 400+2b=240+3b
Solve for b: 160=b</p>

<p>25) 5 integers, average 350, so total # is 5*350= 1750
99+102+103+104+x= 1750 (103 and 104 are smallest possible so the third can be as large as possible)
x=1342</p>

<p>25) The answer is A: d/8c. It says the price is "d dollars for 8 ounces," so that translates to-- price of one ounce = d/8. (the for is used like "per" in this situation, and this means divided by). Each ounce makes c cups of coffee, so in order to find the price for one cup of coffee we have to divide d/8 by c. This makes it d/8c.</p>

<p>24) If the new probability of choosing a blue marble is 2/3, then the new probability of choosing a red marble becomes 1- (2/3) = 1/3. Since the number of red marbles stays the same, we multiply 120 by 3 to get the total number of marbles. This gives us 360, but we have to subtract the original amount (200) to get 160.</p>

<p>thank you very much everyone!</p>

<p>are you REQUIRED to know cups/liters/gallons and all that stuff????</p>

<p>Gandhiji, I highly doubt that CB will require you to know the different unit conversions. If any question involves them, then you will be given the information needed.</p>