forum.virtualchallengemeets.com

Hello all!

Just got some last minute questions before districts regarding calculator. Any and all help will be appreciated. Thank you very much!

12A-28. Daria has 25 coins totaling $2.41. She has twice as many dimes as pennies, and one less nickel than quarters. How many nickels and dimes does she have?

Answer: 15 INTEGER

I assume that there is some way of solving this very quickly without having to write down the equations, substitute, plug in, etc. Can one use matrices for this?

2012-2013 SG:

I am aware that a thread for this has already been created, but it doesn't have all of the problems that I'm having trouble with.

11D-38. Mike and Mary stand unmoving 24 feet apart. Ned stands 18 feet from Mike and 8 feet from Mary, forming a scalene triangle. What is the shortest distance Ned can move to create a right triangle?

Answer: 4.93 FEET

11E-26. Harvey in a city wants to arrange a meeting with Mike in another city which is 95 miles north, and also with Harry who lives in yet another city, 167 miles due east. If the meeting site selected was yet another city which is equidistant from all three towns, how far does each person travel?

Answer: 9.61e1 miles

11F-37. A kid used a clothes pin to attach a playing card to a spoke on the front wheel of his bike. Once every wheel rotation, the card "clicked" when it struck the bike frame yoke. If the front wheel has an 18-in diameter, what is the bike velocity when clicks are 1/4 s apart?

Answer: 1.29e1 MPH

12H-37. A chair was caught up in a tornado, rotating around a 1500 feet circumference with a speed of 110 mph. After picking up the chair, the tornado traveled 5 miles at 35 mph before dissipating. How far did the chair travel?

Answer: 2.07e1 MILES

Thank you!

Give me your e-mail and i'll send a pdf of the solutions to the study list.

EDIT: You can private message me your email address.

I am not sure about matrices. The method I showed above harly takes 2 minutes if you are careful with the equations.

Could you use the 84?

Thanks, 101dalmations. I guess if there's extra time, I could always go back and do those.

Thanks.

Wat's rref?

Uhh...wat?

It's okay. I think I'll just stick with the straightforward way. Thanks anyway.

I was confused with the "Gaussian elimination," but never mind that. Wierd math terms...hmm...

Yeah. People like the nerds at my school tell me to read wikipedia and all that junk to get like more info about math. But I am like disinterested in it cuz partly, it is a waste of my time. However, sometimes the math terms actually help (only if someone tells it to me)...

Usually the people who write stuff on wikipedia, at least I think, are adults who have professional experience with math, so there's absolutely no way for me to understand. Or they could be trolls. Who knows.

Yeah I kinda guessed u would post this nsguy... :P

I'm not sure. Trust me, I've tried before. The assistance of a teacher sure would be helpful. Independent study can only get you so far.

Well, Wikepedia is not that hard. But still, sometimes I think they over analyze a bunch of things. I am in PAP Physics and simply wanted to search up some stuff about single slit diffraction that I did not completely understand. Instead, I frigging found double/triple integrals, some complex numbers, and blah blah blah.......

When I look up some geometry stuff, same thing.

However, I think Blasian Asian and 101dalmations are overdramatizing wikepedia. Its not too complicated and easy to follow for the most part(At least for UIL reasons).

MY best option to gain knowlege however is from nsguy and my teachers. I acknowlege nsguys post about self study though.

I don't think that Wikipedia over analyzes things, especially in math. If anything the problem is exactly the opposite, they generalize too much, because of space limitations and the depth of the material.

The best way to understand that stuff is to build up your basics more, and spread yourself out in different math disciplines. A lot of the stuff on the Wikipedia articles that are relevant to contest honestly don't require more advanced maths, they just require you to know basic ideas and theorems beforehand so you can adapt and catch it quickly.

As someone who relies almost solely on independent studies, I can tell you that if you get a good proof-ridden grounding in your high school math classes and a couple of upper level intro subjects, like linear algebra, abstract algebra, and analysis, then you can understand a lot of the stuff more easily. It's not as daunting as it seems.

Is saying wikipedia is a little hard to understand being dramatic? My apologies.

I suppose I can give it a shot.