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Diophantus's Age

Diophantus's Age

Posers and Puzzles

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This is an old one too, if you have heard it before let a couple of people viewing it for the first time have a go before you post.

Apparently the following is carved on his tomb:

"God granted him to be a boy for the sixth part of his life, and adding a twelth part to this, He clothed his cheeks with down; He lit him the light of wedlock after a seventh part, and five years after his marriage He granted him a son. Alas! late-born wretched child; after attaining the measure of half his father's full life, chill Fate took him. After consoling his grief by this science of numbers for four years he ended his life."

What age was Diophantus when he died?

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Originally posted by demonseed
This is an old one too, if you have heard it before let a couple of people viewing it for the first time have a go before you post.

Apparently the following is carved on his tomb:

"God granted him to be a boy for the sixth part of his life, and adding a twelth part to this, He clothed his cheeks with down; He lit him the light of wedlock after a seve ...[text shortened]... cience of numbers for four years he ended his life."

What age was Diophantus when he died?
He died two years before he was born?

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I got a hair above 14...
14.08917197 to be precise... I feel that's wrong but can't see where...

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Or if I were to be lazy and just go for the realistic common multiple answer, I'd say 84

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D/6 + D/12 + D/7 + 5 + D/2 + 4 = D
[14D + 7D + 12D + 42D]/84 + 9 = D
75D/84 +9 = D
9 = D - 75D/84
9 = 9D/84
84 = D

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Originally posted by SwissGambit
D/6 + D/12 + D/7 + 5 + D/2 + 4 = D
[14D + 7D + 12D + 42D]/84 + 9 = D
75D/84 +9 = D
9 = D - 75D/84
9 = 9D/84
84 = D
Spot on!

Did you hear it before or did you work it out?

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Originally posted by demonseed
Spot on!

Did you hear it before or did you work it out?
I hadn't heard it before, but it wasn't too difficult - just a bit of algebra.