'09 TMSCA #2

[nsguy1350]

Ouch, messed up this one compared to #1. 24 pts lower (well, maybe 32, but I counted one right that the answer key disagreed with, because I just KNOW I am right. I'll post the question to see if you guys agree. I got a 268 (or 260), and I went so SLOW on this test. Normally, I finish with time to go over questions I don't know, but I had only a few minutes when I got to the last page and didn't answer 14 (45 right, 1 wrong, which I knew how to do but rushed and did something terribly dumb.)

Questions:

19. This mathematician is remembered for her important contributions to abstract algebra.
Ans: E.Emmy Noether

20. The harmonic mean of the roots of [unparseable or potentially dangerous latex formula].
I knew how to do this one, but I must've done something wrong!!!! I even answered how to do this type of problem on this forum before, but I couldn't get it on the test! I kept getting -48/23, but it's not an answer choice. :'(. To find the harmonic mean of the roots, simplify [unparseable or potentially dangerous latex formula] where x,y,z are the roots and work from there. Apparently my method didn't work this time! Mus've done a silly mistake :(
Ans: C.-12/23

26. Find the total area of a right circular cylinder with diameter 2 feet and height 42 inches. (nearest tenth)

I know how to do this problem, and the conversions too, but I don't know what went wrong! Ans: E.26267.7 cm^2

29. Joe leaves Garden City and hikes 8.4 miles on a bearing of 117 to the first checkpoint. Then he hikes 7.6 miles on a bearing of 236 to the second checkpoint. How far is it from Garden City to the second checkpoint? (nearest hundredth)

I never skip these either!!!!!!!!!!!!!!!!!!!!!!!!! Ans: A.8.15 mi

35. Six married couples attend the marriage enrichment planning meeting. How many committees of five can be chosen if no committee is to include a husband-and-wife team?
Ans. E.792

37. The circles [unparseable or potentially dangerous latex formula] and [unparseable or potentially dangerous latex formula] intersect at two points. Find the slope of the line through the two points of intersection. (nearest tenth)

C. -2.5

45. (I counted this one right, with 3 instead of 2.) How many asymptotes does [unparseable or potentially dangerous latex formula] have? I believe is is 3 due to x = 2, x = -3/2, y = 3/2.

48. The coordinates of the vertices of triangle ABC are (-2,1),(4,5) and (6,-2). The medians intersect at (x,y). Find x+y.
Ans: B.4

50. A triangle is inscribed in a circle. The lengths of the sides are 8,10, and 12. Find the radius. (nearest hundredth)
E.6.05

52. Six red cards and eight black cards are shuffled together. Two cards are drawn, one right after the other, without replacement. What is the probability that a black card is the second card?

54. Anthony left Wichita Falls for a tournament in Portland, Oregon at 60mph. He had forgetten his cell phone and his competition Frisbee. Two hours later, Chuck left Wichita Falls, with Anthony's Frisbee, on the same route at 65 mph. How far had Anthony traveled before he was overtaken by Chuck?
E.1560 mi

55. A focus of [unparseable or potentially dangerous latex formula] is (x,y). Find y.
B.1

57. Which of the following is a lucky prime number?
C.233

How are we supposed to do lucky numbers quickly?

I FELT SO IMCOMPETENT DURING THE TEST!! :( I need to redeem myself tomorrow :D

[nick3194]

The harmonic mean is the reciprocal of the average of the reciprocals of the zeroes. The zeroes are -.5, -.25, and 4. 1/-.5 + 1/-.25 + 1/4 = -5.75. -5.75/3 = -23/12. The reciprocal of this is -12/23.

On 45, the answer is two. When you factor the numerator, you get (x-2)(3x+4), and when you factor the denominator, you get (x-2)(2x+3). Since x-2 is common on both parts, you can cancel it out. I did the same thing on a test a couple of weeks ago.

[Salvadoramerican]

#35 12C5
#37 subtract the two equations

#48 the median is the average of the x and y values so median is (avg of x, avg of y)

#50 R=(abc)/(4K)
where K= area of triangle and a,b,c are side length

Lucky numbers their is a method but it takes way to long if you want I can elaborate tommorow morning.

#54 65x=60x+2(65) find x
then 65*x= distance

I stink at probability but i can figure it out if you give me the answer, i'll just reverse engineer it because i keep getting .615 for some reason

[Salvadoramerican]

2ft=24in
So (24*2.54)* pi *(42*2.54)+2(12*2.54)^2 * pi

[Salvadoramerican]

You are right their are 2 asymptotes since their is no slant because when factor you elliminate one of the factors

[Salvadoramerican]

harmonic mean of the roots of a cubic equation is -3d/c

[nsguy1350]

Stupid mistakes everywhere, I did the right thing on many but then did bad multiplication or something. I guess I got a 260 then :/ my coach told me that today, and it didn't even enter my mind. Thanks, I'm about to take #3 and #4. Also, a sheet with explanations of some problems (not in-depth, just the work) did not use 12C5 as the answer for 35. I think it's just a coincidence that those values are the same. I knew how to do a lot of these but I made so many dumb mistakes!!!

[Salvadoramerican]

Hey no ones perfect just use your gift, your advantage is that you have an incredibably quick brain which i lack, and don't second guess yourself stay clam during the test thats my advise