BdMO National Secondary 2010#1
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samiul_samin
- Posts:1007
- Joined:Sat Dec 09, 2017 1:32 pm
There are $20$ people in a party excluding you.It is known that you know the same number of people as you don't know.How many of them do you know?
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samiul_samin
- Posts:1007
- Joined:Sat Dec 09, 2017 1:32 pm
Re: BdMO National Secondary 2010#1
Answer:$10$
Let,
Know=don't know=$n$
So,
$n+n=20\Rightarrow 2n=20 \Rightarrow n=10$
Let,
Know=don't know=$n$
So,
$n+n=20\Rightarrow 2n=20 \Rightarrow n=10$