## Regional MO 2016 Dhaka ques 8

Forum rules
Please don't post problems (by starting a topic) in the "X: Solved" forums. Those forums are only for showcasing the problems for the convenience of the users. You can always post the problems in the main Divisional Math Olympiad forum. Later we shall move that topic with proper formatting, and post in the resource section.
Md. Rifat uddin
Posts: 10
Joined: Thu Dec 15, 2016 1:32 pm

### Regional MO 2016 Dhaka ques 8

How many eight digit number can be formed by using the digits \$1, 2, 3, 4, 5, 6, 7,8\$ so that each number has \$6\$ digits in such place where that digit is less than the next digit?

Example: In number \$2314; 2,1\$ are two digits such that each of them is less than the next digit.

super boy
Posts: 5
Joined: Tue Dec 20, 2016 1:11 pm

### Re: Regional MO 2016 Dhaka ques 8

I think the answer is \$7\$

Solution: (If anyone check this if it's wrong or not, I'll be happy )

Nodee Haque
Posts: 2
Joined: Sat Aug 24, 2013 6:46 pm

### Re: Regional MO 2016 Dhaka ques 8

isn't the answear (7+6) = 13 ? since, in the question it said how many 'numbers' can be formed. doesn't it mean that there would be different permutations after choosing the 6 digits?? i'm not sure though...

samiul_samin
Posts: 999
Joined: Sat Dec 09, 2017 1:32 pm

### Re: Regional MO 2016 Dhaka ques 8

Double post.See here