Summer Test #3

webmaster · Administrator

Summer Test #3

webmaster · Administrator

I just noticed what Zack said about his computer needing an AC adapter, so I will post this test here, although I am sure Zack will post his up on his site too. Anyway, here you go!

Summer Test #3

WesBrown · Star Member

Jeez, I got burned on that test. I made so many dumb mistakes....=>177

I only worked so far, but the only error I found was number #24

You have 22.1, should be 2.21.

vvr1590 · Senior Member

Wow!

That was a horribly difficult test... I got killed.

Few questions:

2. 1.235 - 2.18

How do you do that? I always miss questions like these

50. 46^3

60. 143342 (base 5) = __________ (base 10)

That's it...

I won't say my score. You'll see it on the leaderboard. Don't laugh

Vinay

webmaster · Administrator

Hey, I don't want to hear any complaints!!! Remember you asked for a harder test!!!!!

I honestly don't think it was the difficulty of the test that stumped you guys. I made the test a different flow from what you are used to and tried to alter it a little to make the "feel" different. I bet if you did this again a month from now you would do better.

But, it was harder I admit.

WesBrown · Star Member

I'll agree with you on that.

I got burninated because of the dumb mistakes. I missed 3 out of the first 6. Dumb....

mtrmth88 · Star Member

i'll be taking the test in a week or so... im packing for a trip... our youth choir at church is going on tour to the grand canyon and we leave bright and early tomorrow morning. im still not done packing! gah!

so yeah. ill post my annoyingly pathetic score a week late... sorry :D

Date: Jun 9, 2005

Ah-Oh, I guess I am seeing something I am not supposed to see...

I will take the test tomorrow afternoon and it seems like I have to struggle just to get over 200.

Well, Vinay, all I can say about #2 is, switch and subtract and don't forget to put the negative sign.

#50: Vinay, you've memorized 23^3!(you've shown it in yesterday's post) Then why can't you do this? Was it 12197?

#60: Don't add, subtract! Hint: 20000base5 - ? = 143342base5.

Mr. Jones, that sure looked like a HARD test, wait for my pathetic score then.

Best Wishes

webmaster · Administrator

#2) This was put here to make you take time that normally you would zoom through. You have to be careful and just do the math. There is no trick to this one.

#50) 46^3. I would have done 50 x 50 x 38 = 2500 x 38 = 950000 which is almost right in the range. I got this from changing 46 x 46 x 46 to 50 x 50 x (46 - 8) since we added a total of 8 to everything else. Does this make sense???

#60) I thought this would have been easy if you would have thought to use 20000 base 5, because this is dangerously close to 143342 which turns out to be 5^5 x 2 or 10 x 5^4 = 6250.

Austin · Member

Yea, it was different, not hard, but different. Should've taken it later, took it right after I came back from an sleepover (all night gaming) party at a friends house so kinda felt "stoned" the afternoon I took it. O well, at least I found the absolute min. of my score range. Made careless mistakes and took too much time on some problems.

fht · Long-term Member

So ironically, I missed #2 even if I talked about it yesterday. I love #22 because I missed it. I also love #55 because I spent 30 second and decided to skip it(seldom have division and addition been used together on sequence problems). I love them without any sarcasm.

I need some help on #70, which I have no idea how to do, and #79, which I haven't developed an very effective method if there be any.

I like this test very much. The numbers are more peculiarly chosen and shortcuts are more creatively imbued with less error.

Thanks, Mr. Jones and Best Wishes

webmaster · Administrator

#22) There is no reason to miss this one, because if you have 9's repeating it moves it to the next number, so really you are only changing .04 to a fraction which is easy.

#55) Divide by 2 and add 1.

#70) The cubed root of 2914 is very close to 14 and the cubed root of 4192 is close to 16. I would have multiplied them for 224. For safety, I would add about 6 or 7 for 230. Only because 224 is so small you have a small margin for error. Although 224 is within range.

#79) If n is odd then use the formula:
a^2(4a-3), where a=(n+1)/2

If n is even then use the formula:
a^2(4a+3), where a = n/2

So for this one we have n=6, so a=3 and that gives us 3^2(4(3)+3) or 9(15) = 135. Notice this would be -135 if the 6^3 were negative.

Anyone else have any ?'s?

fht · Long-term Member

That's why I said the numbers are chosen peculiarly, on #70, they were so off that I couldn't figure out what you've intended. Well, it's my fault anyway...

Would you explain more on the algebra of #79, thanks.

Best Wishes

webmaster · Administrator

FHT,

I am sorry but I can't for the life of me remember how I came up with that formula. It took me MANY hours last time (about a year and a half ago) to come up with it. I have tried using lots of time now and have only succeeded in coming up with other formulas that don't come close to the other. For example, if n is even you can also use: a(a+1)(4a-1) + a with a=n/2. I have yet to figure out how I came up with a^2(4a+3). Anyway, I am sorry I can't help. It was one of those things I think I got lucky on the first time.

Although, working on it again allowed me to come up with a new trick. Thanks!! I will email it to Mr. White and start including it on my tests.

Anyone else have a different way of doing these problems??