Silliness Quiz - Page 436

Stitchawl · 04-05-2012, 07:18 AM

Frankly, I think you guys are all just making up numbers and posting them to confuse me. I can't believe that there is actually some rhyme or reason behind them...

Stitchawl

pdurrant · 04-05-2012, 07:29 AM

52 = (7+3!)*(5-1)
53 = 3!*(7+1)+5
54 = (3!+1)*7+5
55 = (5+3)*7-1
56 = (5+3)*7*1
57 = (5+3)*7+1

pdurrant · 04-05-2012, 07:36 AM

Quote:

Originally Posted by Stitchawl

Frankly, I think you guys are all just making up numbers and posting them to confuse me. I can't believe that there is actually some rhyme or reason behind them...

OK, it works like this:

We have the numbers 1, 3, 5 and 7. We can use only those numbers, and each one only once, and we must use all of them.

Using those four numbers, we must make an arithmetic expression ('sum') that makes each number from 1 upwards, without missing out any numbers.

So, so get a total of one, we can do it in lots of ways. a simple one

3+5 = 8
8-7 = 1
1*1 = 1 (what we want to get)

(* is multiply)

so

1 = 1*(3+5-7)

We do have more than adding and subtracting, multiplying and dividing. We're also allowed to use factorial (!). This is a really neat shorthand.

1! = 1
2! = 2*1 = 2
3! = 3*2*1 = 6
4! = 4*3*2*1 = 24
5! = 5*4*3*2*1 = 120

using factorial, we can get to big numbers very quickly.

A number that held me up was 52. 52 is 2*2*13, and we don't have any of those numbers in our list (1,3,5,7). Luckily, 3! is 6 and 6+7 = 13 and 5-1 = 4 = 2*2.

So,

52 = 2*2*13 = 4*(6+7) = (5-1)*(3!+7)
3

red_phoenix · 04-05-2012, 07:58 AM

Quote:

Originally Posted by pdurrant

OK, it works like this:

We have the numbers 1, 3, 5 and 7. We can use only those numbers, and each one only once, and we must use all of them.

Using those four numbers, we must make an arithmetic expression ('sum') that makes each number from 1 upwards, without missing out any numbers.

So, so get a total of one, we can do it in lots of ways. a simple one

3+5 = 8
8-7 = 1
1*1 = 1 (what we want to get)

(* is multiply)

so

1 = 1*(3+5-7)

We do have more than adding and subtracting, multiplying and dividing. We're also allowed to use factorial (!). This is a really neat shorthand.

1! = 1
2! = 2*1 = 2
3! = 3*2*1 = 6
4! = 4*3*2*1 = 24
5! = 5*4*3*2*1 = 120

using factorial, we can get to big numbers very quickly.

A number that held me up was 52. 52 is 2*2*13, and we don't have any of those numbers in our list (1,3,5,7). Luckily, 3! is 6 and 6+7 = 13 and 5-1 = 4 = 2*2.

So,

52 = 2*2*13 = 4*(6+7) = (5-1)*(3!+7)
3

That is a great explanation pdurrant but it still doesn't make any sense to me.

Stitchawl · 04-05-2012, 08:01 AM

Thanks Paul...

Unfortunately, I can't even enter a software serial number on the first (or often second) try. My wife helped me set up speed dial on older telephones (before I had a cell phone with a contact list.) Numbers just don't stay where I put them on a page... They tend to swirl around like a Ferris Wheel. Such is the nature of Dyscalculia.

Dyscalculia is like dyslexia for numbers. But unlike dyslexia, very little is known about its prevalence, causes or treatment. But as one who suffers from it, until you learn that it's real, it can seriously screw up one's life! These days I can laugh at it, and have come to terms with my inability to use numbers. But back during my school days I can't tell you all the tears, frustration, accusations about 'not trying hard enough,' etc. I might read a string of numbers to write down, but by the time they reach my pencil they are in a completely different order. I mean completely! I can't even use a calculator with any degree of accuracy. I say one set of numbers (which may or may not be what I'm reading from the paper,) but my fingers push a completely different set.

Oddly enough, I can look at a shopping trolly overloaded full of groceries, and 'guess' the approximate cost and be within a dollar or two every time... I'm happy enough with that.

Stitchawl

pdurrant · 04-05-2012, 08:44 AM

Quote:

Originally Posted by Stitchawl

Dyscalculia is like dyslexia for numbers.

Ah - I have heard of that. And I suspect that, just like dyslexia, it is often a more serious problem for academic school work than for real life.

pdurrant · 04-05-2012, 08:46 AM

Quote:

Originally Posted by red_pheonix

That is a great explanation pdurrant but it still doesn't make any sense to me.

The task is to make sums that add up to each number (1,2,3,...) in turn.

If we were unlimited in the numbers we could use, this would be trivial.

So we are limited to using exactly four specific numbers (1,3,5,7) in our sums.

1*(3+5-7) = 1
1+3+5-7 = 2

etc.

Hamlet53 · 04-05-2012, 09:23 AM

I am happy to see that a number of quiz regulars here understood what I was asking and did so well. So we are up to 57 as follows,dropping duplicates that were posted second in the timeline:

1 = ((5+3)-7)*1 given by me

Quote:

Originally Posted by SneakySnake

2 = (7+3)/5*1 ???

If I understand the Q

3 = (7+5)/(3+1) ???
4 = (7+5)/(3*1) ???
5 = (7+3-5)*1 ???
6 = (7+5)/(3-1) ???
7 = 3*5-1-7 ???
8 = (5+7)-(3+1)
9 = (5+7)-(3*1)
10 = (5+7)-(3-1)

Quote:

Originally Posted by Daithi

11 = ((5!)/(7+3))-1
12 = (5!)/((7+3)^1)
13 = ((5!)/(7+3))+1
14 = 7-1+3+5
15 = 1*3+5+7
16 = 1+3+5+7
17 = 3*7+1-5
18 = (3!)+7+5^1
19 = (3!)+7+5+1
20 = 3*7-1^5

Quote:

Originally Posted by SneakySnake

21 = 3*7*1^5
22= 3*7+1^5
23 = 3*5+7+1
24 = (7+5)*(3-1)
25 = 3*7+5-1 or (7-3+1)*5

Quote:

Originally Posted by Bilbo1967

26 = ((3 * 7) + 5) * 1
27 = ((3 * 7) + 5) + 1

Quote:

Originally Posted by Bilbo1967

28 = (7 * 5) - 3! - 1
29 = (7 * 5) - (3! * 1)
30 = (7 * 5) - (3! - 1)

Quote:

Originally Posted by Bilbo1967

31 = (7 * 5) - 3 - 1
32 = (5! / 3) -7 - 1
33 = (5! / 3) - (7 * 1)
34 = (5! / 3) - (7 – 1)

Quote:

Originally Posted by pdurrant

31 = 5*7-3-1
32 = (5*7-3)*1
33 = 5*7-3+1
34 = (5-1)!+7+3
35 = 7!/5!-3!-1
36 = 3! * (7-5+1)!
37 = 5*(7+1)-3
38 = 7!/5!-3-1
39 = 7!/5!-(3/1)
40 = 7!/5!-3+1

Quote:

Originally Posted by pdurrant

41 = 5*7*1+3!
42 = 5*7+3!+1
43 = 5*(7+1)+3
44 = 7!/5!+3-1
45 = (7+3-1)*5
46 = 7!/5!+3+1
47 = 7!/5!+3!-1
48 = (7+1)*(5+3)

meant (7-1) there Paul?
49 = 7!/5!+3!+1
50 = 1*5*(7+3)

Quote:

Originally Posted by SneakySnake

51 = 5*(7+3)+1

Quote:

Originally Posted by pdurrant

52 = (7+3!)*(5-1)
53 = 3!*(7+1)+5
54 = (3!+1)*7+5
55 = (5+3)*7-1
56 = (5+3)*7*1
57 = (5+3)*7+1

So eliminating duplicates, and disallowing pdurrant's one miscalculation we have:

SneakySnake: = 14

Daithi = 10

Bilbo1967 = 9

pdurrant = 21

I have to be out until tonight so I declare pdurrant the winner.

Stitchawl · 04-05-2012, 09:48 AM

Quote:

Originally Posted by pdurrant

Ah - I have heard of that. And I suspect that, just like dyslexia, it is often a more serious problem for academic school work than for real life.

Quite so. I have difficulty entering serial numbers... but how often do I need to do that? I have difficulty using a calculator, but I only need that about once every 2-3 months...

Quote:

Originally Posted by pdurrant

The task is to make sums that add up to each number (1,2,3,...) in turn.

If we were unlimited in the numbers we could use, this would be trivial.

So we are limited to using exactly four specific numbers (1,3,5,7) in our sums.

1*(3+5-7) = 1
1+3+5-7 = 2

etc.

Wow! I understood that! It's remarkable that it's just the actual numbers that create the difficulty, not the process. But then, that's how I managed to get through 'Financial Management' in my MBA program. The Prof exempted me from actually working out the numbers as long as I could apply the correct process and knew which formula was needed for each scenario.

Stitchawl

Bilbo1967 · 04-05-2012, 10:13 AM

Quote:

Originally Posted by Hamlet53

I am happy to see that a number of quiz regulars here understood what I was asking and did so well. So we are up to 57...

Just out of interest, do you know what the first number that cannot be derived that way is?

orlok · 04-05-2012, 10:50 AM

Quote:

Originally Posted by Stitchawl

Frankly, I think you guys are all just making up numbers and posting them to confuse me. I can't believe that there is actually some rhyme or reason behind them...

Stitchawl

Apologies for reposting this from another thread, but it seems appropriate...

pdurrant · 04-05-2012, 11:45 AM

Quote:

Originally Posted by Hamlet53

So eliminating duplicates, and disallowing pdurrant's one miscalculation

Whoops! And now I must find another quiz question. And a non-arithmetical one, I think:

RS, TO, ND, IR, DR, TH, ...

What's next?

Daithi · 04-05-2012, 11:46 AM

You know Stitchawl, there are three kinds of people in this world -- those who are good with numbers and those who aren't.

pdurrant · 04-05-2012, 05:34 PM

Quote:

Originally Posted by pdurrant

Whoops! And now I must find another quiz question. And a non-arithmetical one, I think:

RS, TO, ND, IR, DR, TH, ...

What's next?

No one?

OK, the next three are

FT, HX, TH, ...

What's next?

Bilbo1967 · 04-05-2012, 05:37 PM

I have to admit to being stumped on this one.

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04-05-2012, 07:18 AM	#6526
Stitchawl Opsimath Posts: 12,344 Karma: 187123287 Join Date: Mar 2009 Location: Chiang Mai, Northern Thailand Device: Sony PRS-650, iPhone 5, Kobo Glo, Sony PRS-350, iPad, Samsung Galaxy	Frankly, I think you guys are all just making up numbers and posting them to confuse me. I can't believe that there is actually some rhyme or reason behind them... Stitchawl

04-05-2012, 07:29 AM	#6527
pdurrant The Grand Mouse 高貴的老鼠 Posts: 74,097 Karma: 315558332 Join Date: Jul 2007 Location: Norfolk, England Device: Kindle Oasis	52 = (7+3!)(5-1) 53 = 3!(7+1)+5 54 = (3!+1)7+5 55 = (5+3)7-1 56 = (5+3)71 57 = (5+3)*7+1

04-05-2012, 08:01 AM	#6530
Stitchawl Opsimath Posts: 12,344 Karma: 187123287 Join Date: Mar 2009 Location: Chiang Mai, Northern Thailand Device: Sony PRS-650, iPhone 5, Kobo Glo, Sony PRS-350, iPad, Samsung Galaxy	Thanks Paul... Unfortunately, I can't even enter a software serial number on the first (or often second) try. My wife helped me set up speed dial on older telephones (before I had a cell phone with a contact list.) Numbers just don't stay where I put them on a page... They tend to swirl around like a Ferris Wheel. Such is the nature of Dyscalculia. Dyscalculia is like dyslexia for numbers. But unlike dyslexia, very little is known about its prevalence, causes or treatment. But as one who suffers from it, until you learn that it's real, it can seriously screw up one's life! These days I can laugh at it, and have come to terms with my inability to use numbers. But back during my school days I can't tell you all the tears, frustration, accusations about 'not trying hard enough,' etc. I might read a string of numbers to write down, but by the time they reach my pencil they are in a completely different order. I mean completely! I can't even use a calculator with any degree of accuracy. I say one set of numbers (which may or may not be what I'm reading from the paper,) but my fingers push a completely different set. Oddly enough, I can look at a shopping trolly overloaded full of groceries, and 'guess' the approximate cost and be within a dollar or two every time... I'm happy enough with that. Stitchawl

04-05-2012, 11:46 AM	#6538
Daithi Publishers are evil! Posts: 2,418 Karma: 36205264 Join Date: Mar 2008 Location: Rhode Island Device: Various Kindles	You know Stitchawl, there are three kinds of people in this world -- those who are good with numbers and those who aren't.

04-05-2012, 05:37 PM	#6540
Bilbo1967 Not scared! Posts: 13,424 Karma: 81011643 Join Date: Mar 2009 Location: Midlands, UK Device: Kindle Paperwhite 10, Huawei M5 10	I have to admit to being stumped on this one.