12) Lê Quốc Trần Anh was born in Knowing that: = 2018 SO HOW OLD IS TRẦN ANH NOW (this year is 2018)

Question by Lê Anh Duy

26/04/2018 at 15:15

12) Lê Quốc Trần Anh was born in \(\overline{abcd}\)

Knowing that: \(\overline{abcd}+\overline{bcd}+\overline{cd}+d\) = 2018

SO HOW OLD IS TRẦN ANH NOW (this year is 2018)

Trần Anh

Alone 29/04/2018 at 01:57

\(1000a+100b+10c+d+100b+10c+d+10c+d+d=2018\)

\(\Rightarrow1000a+200b+30c+4d=2018\)

Because 1000a\(\le2018\)\(\Rightarrow a\le2\) and a\(\ne0\Rightarrow a\in\left\{1,2\right\}\)

With a=1 then \(200b+30c+4d=1018\)

The same \(b\in\left\{0,1,2,3,4,5\right\}\)

+,b=0\(\Rightarrow30c+4d=1018\).Because \(30c+4d\le30.9+4.9=306\) then the expression isn't satisfy

+,b=1\(\Rightarrow30c+4d=818\)(not satisfy)

+,b=2\(\Rightarrow30c+4d=618\)(not satisfy)

+,b=3\(\Rightarrow30c+4d=418\)(not satisfy)

+,b=4\(\Rightarrow30c+4d=218\)

The same:c\(\in\left\{0,1,2,3,4,5,6,7\right\}\).Because \(4d\le36\Rightarrow218-4d\ge218-36=182\)

\(\Rightarrow30c\ge182\Rightarrow c\in\left\{6,7\right\}\)

If c=6 then 4d=38\(\Rightarrow d=\dfrac{19}{2}\)(not satisfy)

If c=7 then 4d=8\(\Rightarrow d=2\)(satisfy)

+,b=5\(\Rightarrow30c+4d=18\)(not satisfy)

With a=2 then 200b+30c+4d=18(not satisfy)

Answer:The old of Le Quoc Tran Anh is:2018-1472=546(years)

OMG,really,miraculous
Lê Anh Duy selected this answer.
Lê Quốc Trần Anh Coordinator 29/04/2018 at 14:49

The answer is very simple: I'm born in 2005, so I'm 13 years old :)