Wednesday 14 October 2009

Four Maths Problems A Week!

The following is a good website for students who love to do interesting/challenging Math problems.
http://www.colstate.edu/mathcontest/index.php

It is hosted by Columbus State University’s College of Education. There are 4 categories: Problem of the Week, Algebra in Action, Middle School Madness and Elementary Brain Teaser.

Questions in the last 2 categories are usually more elementary. I will usually try to solve the problems in the first 2 categories, while my younger sister will attempt questions in the last 2 categories. If you know the answers, you can submit them. Your name will be published immediately (usually within a day) after your answer has been reviewed and it is correct.

There is a problem a week (every Monday) for each category. I chanced upon this website only recently and I like it! You can also try the past problems, or problems in Challenge Mode (where <50% students got the answers correct).

Have fun!

2 comments:

Anonymous said...

I got 2 different answers from different forum for the question below:

Some hot Tiong Bahru Paos (buns) were placed under a transparent plastic hood. After a few minutes , water droplets are observed to be formed on the under surface of the hood. Explain why water droplets are formed on the underside of the plastic food cover.

Answers:

1 - The water vapour from the surrounding air around the bun was heated up and then condensed into water droplets on the cool uderside of the hood.

or

2 - The water vapour from the bun condensed into water droplets on the cool underside of the hood.

Could you advise which one is correct?

Anonymous said...

I THINK the 2nd answer is better. This is because the water in the bun, due to the heat evaporates quickly into water vapour unlike the air which does not really have a lot of water vapour to begin with. Also, water vapour (H20, Relative mass=18) is lighter than the air and would rise.☺☻♥♦♣♠☻☺