Are you smarter than a high schooler in the USSR?

Reply #19

Speler — Sat, 12 Feb 2022 22:51:47 GMT

Great but how did he get to the formula

Reply #18

Speler — Sat, 12 Feb 2022 22:49:59 GMT

The solution:

(7*10^27-21)/29

(7*1000000000000000000000000000-21)/29

(7000000000000000000000000000-21)/29

(6999999999999999999999999979)/29

6999999999999999999999999979/29

241379310344827586206896551

Reply #17

Speler — Sat, 12 Feb 2022 22:40:31 GMT

I gave it a loop:

1 1.6896551724137931034482758620689655172413793103448275862068965517241379310344827586206896551724137931

2 23.4137931034482758620689655172413793103448275862068965517241379310344827586206896551724137931034482759

3 240.6551724137931034482758620689655172413793103448275862068965517241379310344827586206896551724137931034

4 2413.0689655172413793103448275862068965517241379310344827586206896551724137931034482758620689655172413793

5 24137.206896551724137931034482758620689... [ More ]

Reply #16

Speler — Sat, 12 Feb 2022 22:27:36 GMT

7241379310344827586206896551/2413793103448275862068965517=3 // Calculator result.

Reply #15

Speler — Sat, 12 Feb 2022 22:20:57 GMT

Integer N, O; // Make it BigInteger

N= 7*

O= *7

N/3=O

3*O=N

Find smallest N possible.

3 * *7 = 7

Reply #14

cottoneyedjoe — Sat, 05 Feb 2022 22:45:51 GMT

You are smarter than an USSR high schooler

Reply #13

JeetKuneDoLotto — Sat, 05 Feb 2022 20:11:13 GMT

Great work of algebra there.

But the real question is...

And this helps me win lotto how?

P.S. I am going to have to assume your answer is correct, as I have no stinking idea. I could try the math, but I think I will just begin my next

three hour workout, that by probability math standards will only net me a 2/5 win.

Reply #12

db101 — Sat, 05 Feb 2022 17:24:10 GMT

The answer is 7241379310344827586206896551. Here's how I worked it out with a hint from someone else.

Say all the digits after the 7 is some number X. Then the number is 7*10^m + X, where m is another number yet to be determined. When you pop off the 7 and stick it at the end, you get a new number that is 10*X + 7, which is 1/3 of 7*10^m + X. Now you solve for X and get

X = (7*10^m - 21)/29

Now all you have to do is find the right m to make the right hand side a whole number, w... [ More ]

Reply #11

Deedeebod — Tue, 01 Feb 2022 05:36:37 GMT

Reply #10

db101 — Fri, 28 Jan 2022 19:06:00 GMT

I'm gonna give it a try but probably give up and ask my mathy pal. That it can be worked out by hand is probably the big clue.

You should find some old Romanian math contest problems. Behind the iron curtain they cranked out a lot of math whizzes.

Reply #9

cottoneyedjoe — Fri, 21 Jan 2022 15:48:34 GMT

They took math education more seriously than they do here in Trannyfornia, what can I say.

Hint 2: The first seven digits are 7241379 and the last three digits are 551.

Reply #8

AllenB — Fri, 21 Jan 2022 13:18:08 GMT

In Excel The Number conversion is

N CONVERSION RATIO

RIGHT(N,LEN(N)-1)*10+LEFT(N,1)*1 N/CONVERSION

I stopped at 9 Digits but I new it was not exact.

So you are telling us that Russian High Schoolers can solve this without a calculator?

Come on Man,

Let's Go Br____n

Reply #7

cottoneyedjoe — Fri, 21 Jan 2022 04:52:26 GMT

Don't be too hard yourself. I had to use a calculator to work it out. I got whooped by the USSR.

Reply #6

ram — Fri, 21 Jan 2022 04:41:28 GMT

Never said I was the sharpest pencil in the box. That's why I had to guess, I sure didn't know.

Reply #5

cottoneyedjoe — Fri, 21 Jan 2022 04:01:47 GMT

You're getting closer. 72413792/3 = 24137930.66666...

You'll probably figure it soon.

Reply #4

cottoneyedjoe — Fri, 21 Jan 2022 03:59:21 GMT

Yeah, unfortunately 72 is not the right number. I'll go ahead and give a hint:

Hint 1: The answer is 28 digits long (!)

I should also clarify that the procedure is not to reverse the original number, only to put the 7 at the back of the line while the other digits move up 1 position. The 2nd digit becomes the 1st, the 3rd digit becomes the 2nd, etc.

Reply #3

AllenB — Fri, 21 Jan 2022 03:55:08 GMT

72413792 24137927 3

Reply #2

AllenB — Fri, 21 Jan 2022 03:15:06 GMT

the reverse of 72 is 27. 27/72=2.66667

Guess Again

Reply #1

ram — Thu, 20 Jan 2022 20:58:33 GMT

My guess would be 72

Are you smarter than a high schooler in the USSR?

cottoneyedjoe — Thu, 20 Jan 2022 20:03:45 GMT

Here is a math problem from an old Soviet exam for high schoolers. It's much harder than the previous problem I posted, but it does not require any advanced mathematical knowledge. It's intended to be solvable without a calculator or computer, but do as you like. I can post hints tomorrow if anyone needs them.

N is a positive integer whose first digit is 7. If you move the first digit to the last position (i.e., make 7 the new last digit) you get a new number that is exactly one third of N. W... [ More ]