Ok. I have had a chance to properly look over my numbersense test and i am very disappointed with myself. I had sooo many careless errors. Dang. Anyways, i have a few questions.
42) ..., .25, -.09, x, .0324,... is a geometric sequence. The value of x is ? I hate these types of questions. I always skip them because i don't know how to do them. Can someone explain please.
46) If A is 25% more than B and B is 1/3 of C, Then C is what % of A? I got confused and just skipped it. AHHH. Help me please!!!!
57) An acute triangle has integer side lengths of 7 ,11, and x. The smalles value of x is ? I don't know how to do these either. Also, i don't know how to do those obtuse triangle questions that are frequently on the tests. Can someone please explain how they are done in a simple way.
62) 5^1-5^0+5^-1-5^-2+...= I stopped at problem 59 with almost 40 seconds left. I didn't want to answer the estimation question (number 60 which was outrageous). I could've answered a few more, but this and the stupid estimation got in my way. Grrr. Anyway, how do i do this question?
Thank You.
P.S. - I am getting farther on the test now and i am running across many trig questions. Can i have everyone's advise on how to learn all the trig stuff. Will i be able to do it before state? I would love to learn it, but i don't know how to approach it.
42. It's a geometric seq with common ratio of -.6. Divide .0324 by .09, and you'll get the sq of the common ratio, cuz it's (An+2)/(An). And that sq is .36, and because you see the previous terms alter in sign, so the ratio would be negative, ergo, -.6. So, the answer is .09*-.6=-.054. I missed that one because I didn't put the negative sign; I was so wrapd up in th .6 part. 46. Lol, I did it the most old fashioned way--assuming numbers. Let b=4, then C=12, and A=5; answer=C/A=2.4=240% 57. I skipped that one cuz I just didn't feel like it. Say you have a triangle with sides a,b,c. when a^2+b^2=c^2, the triangle's right, when >, acute, when 11^2, turned out to be 9. 60. Yes Number 60 is outrageous, and it's even more outrageous cuz #50 is the same darn type of the problem. It's a lot easier if you sit in the tranquil sunshine and think about it without a time limit. 62. View it as the summation of a geometric seq with 1st term of 5 and a common ratio of -1/5. Using the summation formula for infinite convergg geom'c seq. An/(1-r)=5/(1--1/5)=25/6 As to the trig stuff, if you've not been in pre-cal yet, check out a precal book and read the section on the trig identities and properties.
Good to see you're getting better really quickly, keep up the good work!
Thanks. I appreciate it! My goal isn't accomplished yet. I need a 200! I was ranked sixth in the state of 3A. Not much of an accomplishment, but eh. The people who beat me were all seniors, so i am happy about that. I can't believe i am going to state. Congrats to you. I saw that you were first in the state of 4A. I am trying really hard to improve my score. At district a made a lousy 140. My score went up 56 points to a 196 at regionals. I was kinda proud of myself.
Anyways, thank you and best wishes in your preparations for state.
Yeah, 3A's got a Zack Barnhart this year, that guy is freakn crazy. He tied me in math and was 2 questions behind me in NS. Whew! That was close. This year 2A and 3A got an excellent throng. Last year there was Kevin Burnnett, and he was it and all. For the past 4 to 5 years NS has been 4A-5A-2A-3A-1A, now it seems to be 5A-3A-2A-4A-1A. The AuSmith-Stripling-Compean-Fitzgerald era is over, sigh, those were the goodol times.
To add to what Sam said on 46... I derived a fast shortcut for these types of problems.
Step 1 --> change the the two numbers into numbers that you can multiply them together. For example, say they say A is 10% more than B and B is 20% less than C. If the decimal value doesnt lend itself easy to be multiplied in your head, then change it into a fraction.
Your first number is 1.1 (1+10%) and your second number is .8 (1-20%).
Step 2 --> after multiplying the two numbers together, you'll end up with either your answer or the inverse of your answer. If they want A of C, then you'll just need to right down the product of the two numbers. If they want C of A, then you'll take the inverse of the product.
I like to think about the last letter presented. If you see the letter C, then the answer is EASY (sounds like a C). And if you see the letter A, its the inverse.
so from our example, if they wanted to know A of C, then the answer is 1.1*.8 which equals 88%.
If you want C of A then you take the inverse, you'll start with 88/100 --> 11/25 and then you'll take the inverse of that which is 25/11 --> 2 3/11 which is 227 3/11%.
On the one that was on the region test, you have 5/4 * 1/3 --> 5/12. Now since they asked for C of A you'll get 12/5 which is 240%.
As for the trig stuff. It is definately worth learning. I want you to go borrow a precalculus book from school. You're gonna go through each section with a fine toothed comb. One section a night. Make sure you get it all down. You'll need to memorize basic sin, cos, and tan measures (15, 30, 45, 60, 90, etc... and be sure to memorize it all in radians too). Also be sure to master double angles, basic identies, and anything else you can cram into your head. You'll find it'll pay off dearly once you crack the 60s in state. If you need any help on specifics, ask Sam, Brad, or me. We'll be happy to help, but I think you'll learn it better if you can figure it out by yourself first and then ask for clarification.
Hehe. If i can just get a few more questions and not get nervous at state....That would be awesome. I think i can do it. I guess i have to be confident in myself.
