## Chittagong Secondary 2017#4

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

### Chittagong Secondary 2017#4

In a \$2015×2\$ chess board,what is the maximum number of horses we can put such that no horses attack each other?

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

### Re: Chittagong Secondary 2017#4

Hint

Akash7
Posts: 5
Joined: Thu Mar 15, 2018 10:31 am
Location: Dhaka

### Re: Chittagong Secondary 2017#4

samiul_samin wrote:
Sat Feb 24, 2018 1:53 am
Hint
Sorry brother,your solution is not right .It doesn't mean that if there are 2015 black squares then there can be placed 2015 horses at the maximum rate.First think about 5*2 chessboard.You can put at most 4 horses in 5*2 chessboard such that no horse attack each other.Then add up 403 such chessboards to get a 2015*2 chessboard.So you can put at most 403*4=1612 horses in 2015*2 chessboard which meets the given condition.

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

### Re: Chittagong Secondary 2017#4

Akash7 wrote:
Wed May 02, 2018 8:03 pm
samiul_samin wrote:
Sat Feb 24, 2018 1:53 am
.First think about 5*2 chessboard.You can put at most 4 horses in 5*2 chessboard .
WHY ?? I can put 5 knights in that boat.

Akash7
Posts: 5
Joined: Thu Mar 15, 2018 10:31 am
Location: Dhaka

### Re: Chittagong Secondary 2017#4

No,you can't Check practically in a real chessboard.

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

### Re: Chittagong Secondary 2017#4

Can you give detailed solution?

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

### Re: Chittagong Secondary 2017#4

Akash7 wrote:
Wed May 02, 2018 8:03 pm
samiul_samin wrote:
Sat Feb 24, 2018 1:53 am
Hint
Sorry brother,your solution is not right .It doesn't mean that if there are 2015 black squares then there can be placed 2015 horses at the maximum rate.First think about 5*2 chessboard.You can put at most 4 horses in 5*2 chessboard such that no horse attack each other.Then add up 403 such chessboards to get a 2015*2 chessboard.So you can put at most 403*4=1612 horses in 2015*2 chessboard which meets the given condition.
Both of us was wrong .