Math CHALLENGE...Post the hardest math SAT I questions you can find..

Test Preparation
61

<p>What if the smaller cube's side is 20% shorter then the larger one's?</p>

62

<p>WHEW! I got so worried that I was forgetting easy math...thank you!</p>

63

<p>After you done with the second question (if you feel like it), try using 1 for the smallest side in both quesrions. Then check out the tip in #33.</p>

64

<p>small cube= cube 1
next one= cube 2 repres. by x
cube 1 side = s
s= x - .2x = .8x, x = s/.8 = s/(4/5)=5/4 times s
x= 5s/4
cube 5, (5/4)^4--> 625/256 times 3.14 is side of cube 5
vol. cube 5 (625/256)^3 times 3.14^3
vol. cube 1 (3.14)^3
(625/256)^3 is 14.5519----->IS IT CORRECT???</p>

65

<p>k^3 with volume...how do I apply this short-cut?</p>

66

<p>Ohhhh Its Sooo Obvious Now!
80% Is ((5/4)^4)^3 So (5/4)^12 Which Is 14.5519 Whoa!</p>

67

<p>(5/4)^12 is the right answer - you got it right, good and fast job!</p>

68

<p>Hey thanks! Everyone keep these short-cuts coming...this thread will NEVER DIE TILL WE ALL OWN MATH SAT WITH 800s (and destroy the curve in the process)!!!!!</p>

<p>Curve 1-3 yrs from now:
800
760
730
700
670</p>

69

<p>Congrats, hyper! Feeling hyper?
Don't even need to bother with the surface areas ratio.</p>

70

<p>POST NUMBER 69 MATH IS THAT SEXY!!!!</p>

<p>with sides still same stuff (5/4)^4 times 3.14
sur areas ratio:
6<em>((5/4)^4)^2</em>3.14^2
_____________________ is (5/4)^8 for the answer...
6*(3.14)^2</p>

<p>or simply recognize that formula is same for both so cancel 6 and 3.14^2</p>

71

<p>69 replies now 70 keep the sexy math comin'</p>

72

<p>I don't think anyone answered the question from post 47; if so...here it is again anyway. I believe the answer is 2^7 or 128.</p>

<p>Theres a trick for these types of problems...take the prime factorization of the number you are dealing with, find the powers of each "term" (dont know what else to call them), add one to each and multiply them all together. This stems from the idea that each factor can have either 0, 1, 2, ..., k-1, k (where k is the power) of that number as a factor.</p>

73

<p>QUOTE FROM ABOVE: "Curve 1-3 yrs from now:
800
760
730
700
670"</p>

<p>It already is. Did you take the PSAT last year? 80, 76, 73, 70 I think it was.</p>

74

<p>You don't need sides measurments as long as the question is about the ratios.
For question on areas: sides' ratio is k=(5/4)^4 (no matter if small side is 3.14 or 4.13 or 1).
The TIP from post #33 says: areas' ratio is k^2 = ((5/4)^4)^2 = (5/4)^8.
If you know this formula, you'll never need to deal with canceling (and with chances of making a mistake).</p>

75

<p>okay thx I'll remember that...</p>

76

<p>so 1-3 yrs from now
800
740
700
660
630</p>

77

<p>2^7 is the answer to #47.</p>

<p>This method gives you 1 sec solution to #39 question:
2^3=8.</p>

<p>How about #50?
Should be easy now.</p>

78

<p>Why limit yourselves to SAT I hard math questions? Go to <a href="http://www.artofproblemsolving.com/Forum%5B/url%5D"&gt;www.artofproblemsolving.com/Forum&lt;/a>, and if you think the humility on this site is bad...but I'll bet you can pick up some pretty cool math tips on that site, provided you don't get scared away by the IMO & Putnam people...</p>

79

<p>Try this one....</p>

<p>x=sqrt(30-(sqrt30-(sqrt30-(sqrt30...</p>

<p>Solve for x.</p>

80

<p>Do you mean x = sqrt(30-sqrt(30-sqrt(30-sqrt(30... ?</p>

<p>if so, x = sqrt(30 - x)
x^2 = 30 - x
x^2 + x - 30 = 0
(x - 5)(x + 6) = 0
x = 5, -6</p>