It was my understanding there would be no math....

"ttyymmnn" (ttyymmnn) 06/25/2020 at 17:43 • Filed to: None

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34

Hey Oppo, help out me and my son with this basic math problem. We’re close, but I can’t quite make the jump.

1) Let n represent the number of minutes an eruption lasts. Write an expression using the variable n that could be used to determine the waiting time until the next eruption.

2) Use your expression to determine the number of minutes a visitor to the park must wait to see another eruption of Old Faithful after a 12-minute eruption.

>>>>>>>>>>>>>>>>>>>>>

I’m pretty sure you start with n = 46, which means that 2 n = n + 12. But that’s as far as I can get.

Future next gen S2000 owner > ttyymmnn 06/25/2020 at 17:47

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Eruption wait time  = 46+(N-1)*12

Snuze: Needs another Swede > ttyymmnn 06/25/2020 at 17:48

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y = 46+12(n-1) => y = 38 + 12n

where y is the time between eruptions and n is the length of eruptions

ttyymmnn > Future next gen S2000 owner 06/25/2020 at 17:48

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Future next gen S2000 owner > Snuze: Needs another Swede 06/25/2020 at 17:48

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Hah! I won by a minute.

Snuze: Needs another Swede > Future next gen S2000 owner 06/25/2020 at 17:49

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Yeah, but I’m drunkj!

And also correct!

ttyymmnn > Snuze: Needs another Swede 06/25/2020 at 17:49

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Khalbali > ttyymmnn 06/25/2020 at 17:49

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Waiting time=12n+34?

Rusty Vandura - www.tinyurl.com/keepoppo > ttyymmnn 06/25/2020 at 17:50

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You put this out to Oppo without calling Uncle Rusty first?

Future next gen S2000 owner > Snuze: Needs another Swede 06/25/2020 at 17:51

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Nice. I also didn’t reduce mine. Think the teacher will take points off?

Edit: Your reduction is wrong. 34 not 38. You are totally schwasted.

ttyymmnn > Rusty Vandura - www.tinyurl.com/keepoppo 06/25/2020 at 17:52

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My smarter half said to call Uncle Rusty, I thought I’d ask the hive. Maybe we could call and you could explain it. 

MoCamino > ttyymmnn 06/25/2020 at 17:53

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t = time until next eruption
n = length of last eruption
t = 34 + 12n

Pretty sure that will get you there.  

Snuze: Needs another Swede > ttyymmnn 06/25/2020 at 17:53

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okay, this is a 2 variable problem - time erruption lenght (n) and time between erruptions, so lets give that a variable name (y).

y is directly related to n... but how?

well when n = 1, y = 46, and when n = 2, y = 58, but you could also right that as 46 (n=1) + 12 times the difference between y when n =1 and n = 2

So now turn that into a formula - y = 46 (when n=1) + 12 times (n-1) It has to be n - 1 because its 46 when n = 1, so when n = 2 it’s 12 times 1, not 12 times 2 (this is an indexing thing, if you’re familiar with computer science).

so y = 46 + 12 (n -1) but we can expand that to y = 46 + 12n - 12 = 34  + 12n

Q.E.D.

Snuze: Needs another Swede > Future next gen S2000 owner 06/25/2020 at 17:55

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Think the teacher will take points off?

!!! UNKNOWN CONTENT TYPE !!!

Edit: Your reduction is wrong. 34 not 38.

I’m willing to call a truce if you are...

Future next gen S2000 owner > Snuze: Needs another Swede 06/25/2020 at 17:55

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y = 46 + 12n - 12 = 3 8 4   + 12n

1 million points off.

ttyymmnn > Snuze: Needs another Swede 06/25/2020 at 17:55

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But wait, you’re drunk....

If only EssExTee could be so grossly incandescent > ttyymmnn 06/25/2020 at 17:56

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This also holds true for sex eruptions

Snuze: Needs another Swede > ttyymmnn 06/25/2020 at 17:56

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It’s mostly right!

Look, I used to operate nuclear reactors.  I know what I’m doing!!!!!

Future next gen S2000 owner > Snuze: Needs another Swede 06/25/2020 at 17:56

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I’ll drink to that.

ttyymmnn > If only EssExTee could be so grossly incandescent 06/25/2020 at 17:57

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That had not escaped me....

ttyymmnn > Snuze: Needs another Swede 06/25/2020 at 17:58

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My wife understood your explanation, and that’s all that really matters. She’s the math adult in the family. 

Rusty Vandura - www.tinyurl.com/keepoppo > ttyymmnn 06/25/2020 at 18:05

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Talk in an hour or so? Also, can you shoot me a picture of the prompt that goes with the table?

Snuze: Needs another Swede > ttyymmnn 06/25/2020 at 18:07

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“math adult”

I like this. I asked my wife, she said that I am the “math adult” in our family.  Which is a scary proposition...

RPM esq. > Snuze: Needs another Swede 06/25/2020 at 18:14

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Boo it’s 34+12n

Snuze: Needs another Swede > RPM esq. 06/25/2020 at 18:15

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Future next gen S2000 owner already dinged me on that.  

RPM esq. > Snuze: Needs another Swede 06/25/2020 at 18:18

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ha, I hadn’t expanded the “load more comments” to see that ...just worked it out myself extremely painstakingly (me no math good) and scrolled down to comment my solution , and s aw your comment first.

Snuze: Needs another Swede > RPM esq. 06/25/2020 at 18:20

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I’m drunk and also did it really fast.  

Honestly, in the real world we’d call that an “engineering approximation ” and it’s close enough. 

ttyymmnn > Rusty Vandura - www.tinyurl.com/keepoppo 06/25/2020 at 18:22

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Talking with the birthday girl at 6 CDT. Maybe later? No big rush. No. 1 son is fighting boredom by doing math of all things. You should be proud.

ttyymmnn > Snuze: Needs another Swede 06/25/2020 at 18:24

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I handle the artistic, writing/grammar, and  history duties, she tackles math and science. The division of labor works well.

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > ttyymmnn 06/25/2020 at 18:34

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Rusty Vandura - www.tinyurl.com/keepoppo > ttyymmnn 06/25/2020 at 18:40

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I totally am. Buy him a subscription to IXL.

ttyymmnn > 415s30 W123TSXWaggoIIIIIIo ( •_•))°) 06/25/2020 at 18:49

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Pretty much.

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > ttyymmnn 06/25/2020 at 18:55

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I suck at math now, with rigging I shoot a laser and get my first cable length and then adjust with chain as I go. I think I only took statistics in college for the requirement. 

facw > ttyymmnn 06/25/2020 at 21:40

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I assume this is already solved in someone else’s comment, but for my own fun, you observe that every minute of length increases the time to next eruption by 12 minutes. This means that you have:

x = 12l + c

Where x is the time to next eruption, l is the length of eruption, and c is some constant.

First solve for c by plugging in any of the pairs of values above (e.g 46 = 12(1) + c, so c = 46 - 12, and c = 34, or 82 = 12(4) +c, c = 82 - 48, c=34) so you have:

x = 12l + 34

So now you just need to plug 12 into your equation to solve for x where l=12:

x =12(12) + 34

x = 144 + 34

x = 178

So after a 12 minute eruption, you need to wait around 3 hours (178 minutes) for the next one. Maybe take a hike and come back later...

Unless I screwed something up.

ttyymmnn > facw 06/25/2020 at 22:08

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Thanks. My eyes sort of glaze over with this stuff. I’m setting up a Skype with Uncle RustyVandura, who is a math teacher.