Math Trivia

It was funny I bumped into this Math question last week. The daughter of my housemate is in the 4th grade. (Btw, not sure if housemate is an acceptable term, probably people here just pick it up from Pinoy Big Brother :)) Anyway, this 4th grade girl usually has some Math or Science homeworks and she sometimes asks me for help.

For Math, the past questions are not so difficult, usually questions that you can answer with just a glance, if you know what i mean. Example, a drawing of a triangle, angle A=35, angle B=85, angle C=?.

Then one night she showed me this question:
A piece of wire 18m long is used to form different rectangles. There are 4 possible rectangles that can be formed. Give the corresponding area of the 4 rectangles.

Hehe napaupo ako at kumuha ng lapis at scratch paper. Nakakahiya naman if an Engg grad cannot solve a grade school level Math question.

The first thing I had in mind was to use X&Y in solving. However after writing the first equation, I got stucked, I cannot think of another one based on the problem. (You need 2 equations to solve 2 variables right?) If you can solve the above question in 30 seconds, then probably you're a genius. :)

Start solving it now.... :p I'll post the answer some other time. It's actually not that difficult, medyo confusing lang sa simula.
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They also have some weird Science questions. (suko ako d2) Example:
Joe's heartbeat before using the treadmill is 80/minute. After 15 minutes in the treadmill, his heartbeat rises to 130/minute. What is the cause of change?
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'Malay ko'! What is the scientific explanation behind the respiratory system?! I cant remember. :) Is this some sort of oxygen intake, inhale-exhale acceleration thing?

:p