## Dhaka Junior 2011/8

Problem for Junior Group from Divisional Mathematical Olympiad will be solved here.
Forum rules
Please don't post problems (by starting a topic) in the "Junior: Solved" forum. This forum is only for showcasing the problems for the convenience of the users. You can 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.
Moon
Site Admin
Posts: 751
Joined: Tue Nov 02, 2010 7:52 pm
Location: Dhaka, Bangladesh
Contact:

### Dhaka Junior 2011/8

8. Abir started at $9:30$ pm from his house to go to Nayel’s house. When he reached there, he saw it was $8:55$ pm in Nayel’s clock. He started back towards his house when it was $9:00$ pm at Nayel’s. He reached at his house when it was $10:15$ pm in his clock. If Abir needed equal time to go and come back, find out the number of minutes Nayel’s clock is slow by.
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin

Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.

Mehfuj Zahir
Posts: 78
Joined: Thu Jan 20, 2011 10:46 am

### Re: Dhaka Junior 2011/8

55 minutes slow.

nowshin tasnim
Posts: 2
Joined: Sat Dec 10, 2011 1:12 pm

### Re: Dhaka Junior 2011/8

Mehfuj Zahir wrote:55 minutes slow.
please show method .

nafistiham
Posts: 829
Joined: Mon Oct 17, 2011 3:56 pm
Location: 24.758613,90.400161
Contact:

### Re: Dhaka Junior 2011/8

the total time abir took is $9:30-8:55=45$ minutes.in it he stayed $5$ minutes in nayel's house. so he needs $20$ minutes to reach nayel's house.so, when he reaches nayel's house abir's clock said it was $9:50$ when nayel's clock it was $8:55$
so his clock is $55$ minutes slow
$\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0$
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.