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# Speakers Corner

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# How good is your maths

bumpkin
Resolved

Likes # 0

I was asked if I had a HDMI cable which I do but they are not all the same obviously. I use HMDI as an example,the same applies to any connector.Here comes the maths bit. If there are connectors, one big and one small, one male and one female how many cables would be needed to satisfy any situation without inter connection or adapters. Long time since I studied maths but I make it 27,how about you? Now introduce a medium size and then what is the answer. Just a fun question. There is no doubt a formula for this sort of thing if anyone can remind me.

Chronos the 2nd

Likes # 1

Oh dear, I did not even understand the question. Lol.

wiz-king

Likes # 0

The actual number is irrelevant, Murphy's Law states you wont have the one you want in stock!

chub_tor

Likes # 0

bumpkin - you are correct there are duplicates in my 16 as for example Lm-Sf is the same as Sf-Lm and that brings it down to 10

Sm-Sm

Sm-Sf

Sm-Lm

Sm-Lf

Sf-Lf

Sf-Sf

Lm-Lm

Lm-Sf

Lm-Lf

Lf-Lf

Any other solutions anyone?

Aitchbee

Likes # 0

The 4 Identical-twin pairings are ... suspect?

bumpkin

Likes # 0

wiz-king, you would have the ONE in stock if you needed TWO. Aitchbee, why suspect?

spider9

Likes # 0

There are six possible 'ends' - Males, L,M &S plus Females, L, M &S.

Think of them as 1,2,3...etc

Using number pairs, 1-1,1-2,1-3,1-4,1-5,1-6 giving 6 pairs

Then 2-2,2-3,2-4,2-5,2-6 giving 5 pairs

Then 3-3, 3-4, 3-5, 3-6 giving 4 pairs

Then 4-4, 4-5, 4-6 giving 3 pairs

Then 5-5,5-6 giving 2 pairs

Finally, 6-6 giving one pair.

Total 6+5+4+3+2+1 = 21

hastelloy

Likes # 0

chub_tor

2 from 4 is 6 - you are getting 10 because you are using 2 together (eg Sm-Sm, Lm-Lm etc) which adds another 4.

spider9

2 from 6 is 15 - you are getting 21 because you are using 2 together (eg 1-1, 2-2, 3-3 etc) which adds another 6.

spider9

Likes # 0

marvin42

But surely there might be need of cables with identical ends? Or am I misunderstanding the question?

bumpkin

Likes # 0

spider9, there will be cables that require the same connector at both ends, quite often the norm. Thia is the bit that is not considered in the answer 6. A with B,C or D = 3, B with C or D = 2, C with D = 1 There is no AxA, BxB, CxC or DxD which gives the other 4 making 10. Your earlier posting based on small medium and large ie 6 different connectors was very easy to understand and could be applied to any number, applied to 4 it gives the answer 10.

BRYNIT

Likes # 0

I get 9 options.

1. L/M - L/M
2. L/M - S/M
3. L/M - S/F
4. L/F - L/F
5. L/F - S/F
6. L/F - S/M
7. S/F - S/F
8. S/M - S/M
9. S/M - S/F