BdMO National Junior 2014/2

Discussion on Bangladesh Mathematical Olympiad (BdMO) National
samiul_samin
Posts:1007
Joined:Sat Dec 09, 2017 1:32 pm
BdMO National Junior 2014/2

Unread post by samiul_samin » Fri Feb 16, 2018 3:13 pm

How many four digits numbers are there for which ,the number formed by its last two digits in the same order when multiplied by four gives us the number formed by its first two digits in the same order?For example, $4812$ is such a number where the number formed by the last two digits in the same order is $12$ and when multiplied by $4$ gives $48$.
Last edited by samiul_samin on Fri Feb 16, 2018 3:44 pm, edited 1 time in total.

samiul_samin
Posts:1007
Joined:Sat Dec 09, 2017 1:32 pm

Re: BdMO National Junior 2014/2

Unread post by samiul_samin » Fri Feb 16, 2018 3:16 pm

Hint
$2\times 4 =8$; $25\times 4=100$
Answer
$\fbox {22}$

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