Man's Age Now: Find Out His Digit Sum Born Year

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Discussion Overview

The discussion revolves around determining the current age of a man based on the relationship between his age in 2011 and the digit sum of his birth year. The problem is framed as a mathematical reasoning challenge, with participants exploring the implications of the given conditions.

Discussion Character

  • Mathematical reasoning

Main Points Raised

  • One participant states that if the man was born in 1991, then in 2011, his age would be calculated as the digit sum of his birth year, which equals 20 years.
  • Another participant seeks clarification on how to determine the man's current age in 2015 based on the previous information.
  • Repeated inquiries about the man's age in 2015 suggest a focus on extending the calculation beyond the initial year of 2011.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the current age of the man in 2015, as the discussion primarily revolves around the calculations and implications of the age in 2011.

Contextual Notes

The discussion does not resolve how to calculate the age in 2015 based on the information provided, leaving assumptions about the method of extending the age calculation unaddressed.

Albert1
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A man found (at year 2011) his age at that time was all the digit sum of the year when he was born,
can you tell me ,how old is he now ?
 
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Albert said:
A man found (at year 2011) his age at that time was all the digit sum of the year when he was born,
can you tell me ,how old is he now ?
[sp]The man was born in the year 1991 so that in the year 2011 his age was 1 + 9 + 9 + 1 = 20 years ...[/sp]

Kind regards

$\chi$ $\sigma$
 
the sum of digits cannot be > 28 as 3 digit number < 2011 largest sum of digits (1999) is 28
so the year is 19ab or 20cd ( digit positions)

take 19ab.
now 10 a+ b + 1+ 9 + a + b = 111
or 11a + 2b = 111 so a is odd
a = 9 , b = 1 giving 1991
a = 7 or below give b > 9 not possible

take 20cd
so 10c + d + 2 + c + d = 11
11c + 2 d = 9
c = 0 and d = fraction
so no solution
so only solution 1991 and age = 20
 
I mean how old is he now ?(year 2015)
 
Albert said:
I mean how old is he now ?(year 2015)

24 years now
 

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