49 replies to this topic

[araver]

Spoiler for

Even a hint of a solution to this continues to elude me. Does the operation affect two digit numbers differently than single digit numbers?

Spoiler for

The operation is essentially the same, regardless of the number of digits

Adding another example to the challenge:

4 *&* 8 = 6
20 *&* 5 = 12
8 *&* 31 = 34
15 *&* 2 = 9
80 *&* 31 = 62
71 *&* 40 = 86
83 *&* 13 = 94
50 *&* 11 = 30
40 *&* 42 = 28
21 *&* 20 = 20
22 *&* 12 = 14
2 *&* 36 = 13
-------------
44 *&* 47 = ?

[araver]

Adding another example to the challenge:

4 *&* 8 = 6
20 *&* 5 = 12
8 *&* 31 = 34
15 *&* 2 = 9
80 *&* 31 = 62
71 *&* 40 = 86
83 *&* 13 = 94
50 *&* 11 = 30
40 *&* 42 = 28
21 *&* 20 = 20
22 *&* 12 = 14
2 *&* 36 = 13
80 *&* 81 = 86
-------------
44 *&* 47 = ?

[araver]

Adding another example to the challenge:

4 *&* 8 = 6
20 *&* 5 = 12
8 *&* 31 = 34
15 *&* 2 = 9
80 *&* 31 = 62
71 *&* 40 = 86
83 *&* 13 = 94
50 *&* 11 = 30
40 *&* 42 = 28
21 *&* 20 = 20
22 *&* 12 = 14
2 *&* 36 = 13
80 *&* 81 = 86
10 *&* 14 = 10
-------------
44 *&* 47 = ?

[curr3nt]

Spoiler for playing with factors...

Is it 66?

[araver]

Spoiler for playing with factors...

Is it 66?

Care to say why? (in a spoiler of course)

[Darth Legion]

Spoiler for Oh

I should have thought of looking for factor anomalies.

[curr3nt]

Spoiler for kind of guessed

Started with prime - 1
83 *&* 13 = 94 --- (83-1) + (13-1) = 94

So went with N - ? for each number

Started filling in the ones with prime numbers
20 *&* 5 = 12 --- (20-12) + (5-1) = 12
8 *&* 31 = 34 --- (8-4) + (31-1) = 34
80 *&* 31 = 62 --- (80-48) + (31-1) = 62
71 *&* 40 = 86 --- (71-1) + (40-24) = 86
50 *&* 11 = 30 --- (50-30) + (11-1) = 30

The ? shares some common denominators
Except 15 *&* 2 = 9 --- (15-7?) + (2-1) = 9
Which I pretended wasn't there...

Figured
22 *&* 12 = 14 --- (22-12) + (12-8) = 14

With what I had
44 *&* 47 = ? --- (44-?) + (47-1) =

Guessed ? was 24 from 22 *&* 12 = 14

Making
44 *&* 47 = ? --- (44-24) + (47-1) = 66

Basically... not sure how it works. I'm just making things up.

Edited because tabs do not work, neither do spaces...

Edited by curr3nt, 11 January 2011 - 03:16 AM.

[araver]

Spoiler for kind of guessed

Started with prime - 1
83 *&* 13 = 94 --- (83-1) + (13-1) = 94

So went with N - ? for each number

Started filling in the ones with prime numbers
20 *&* 5 = 12 --- (20-12) + (5-1) = 12
8 *&* 31 = 34 --- (8-4) + (31-1) = 34
80 *&* 31 = 62 --- (80-48) + (31-1) = 62
71 *&* 40 = 86 --- (71-1) + (40-24) = 86
50 *&* 11 = 30 --- (50-30) + (11-1) = 30

The ? shares some common denominators
Except 15 *&* 2 = 9 --- (15-7?) + (2-1) = 9
Which I pretended wasn't there...

Figured
22 *&* 12 = 14 --- (22-12) + (12-8) = 14

With what I had
44 *&* 47 = ? --- (44-?) + (47-1) =

Guessed ? was 24 from 22 *&* 12 = 14

Making
44 *&* 47 = ? --- (44-24) + (47-1) = 66

Basically... not sure how it works. I'm just making things up.

Edited because tabs do not work, neither do spaces...

curr3nt, I like the way you deduced it - it's by no means simply a lucky guess. But the operation is not solved yet.

So, adding your answer to the known examples + a new one.
And changing the challenge to another question.

4 *&* 8 = 6
20 *&* 5 = 12
8 *&* 31 = 34
15 *&* 2 = 9
80 *&* 31 = 62
71 *&* 40 = 86
83 *&* 13 = 94
50 *&* 11 = 30
40 *&* 42 = 28
21 *&* 20 = 20
22 *&* 12 = 14
2 *&* 36 = 13
80 *&* 81 = 86
10 *&* 14 = 10
44 *&* 47 = 66 (solved by curr3nt)
60 *&* 40 = 32
-------------
96 *&* 91 = ?

Edited by araver, 11 January 2011 - 06:34 AM.

[curr3nt]

Spoiler for my table is filling out more...

Noticed a pattern with numbers having 2 factors (excluding 1 and itself) with one of them being 2.

N - X pairs
4 (2*2) - 2
10 (2*5) - 6
14 (2*7) - 8
22 (2*11) - 12
This leads me to believe
6 (2*3) - 4 because the number subtracted is the largest factor + 1...except for (2*2)... can we get an example with 9 or 25 as one of the numbers?

Also multiplying the number by 2 multiplies the other number by 2 if 2 is a factor in the original number
10 - 6
20 - 12
40 - 24
80 - 48
also
22 - 12
44 - 24

If 6 - 4 then
12 - 8 (known)
24 - 16
48 - 32
96 - 64

So 96 *&* 91 is (96 - 64) + (91 - ?)

Now we come to the 15 - 7 pair. In the cases above other than 2*2 it could be the two factors added together minus one. 15 would be 3*5 which would be 5+3-1 to get the 7.

91 is 7*13 so would the number subtracted be 7+13-1 or 19?

Making it (96 - 64) + (91 - 19) = 104?

[curr3nt]

Spoiler for sorry for the double post but edit time appears to have past

The pair 42-30 is throwing me off now. It has me thinking 14-8 should be 14-10 but that makes 10-4 which throws off 20-12, 40-24 and 80-48.

Unless something else happens with unique factors. Maybe an example with 28 and one with 63?

Also, thinking I should be in bed asleep right now...

btw, this is fun araver thanks!