Thursday, April 17, 2014

Day 90: Watermelon

From Richard Wiseman:

I have a 100 pound watermelon laying out in the sun. 99% of the watermelon’s weight is water. After a few hours 98% of the watermelon’s weight is water. How much water evaporated?


The answer, slightly obscured for the sake of any who want to solve on their own, is 1100102 pounds – but can you explain why?

Wednesday, April 16, 2014

Day 89: Gun Deaths in Florida


You can take it from here ...

Tuesday, April 15, 2014

Day 88c: Combinations. One more Twist.

We've seen this a couple of times now.

What if I had a white marker, one that didn't show, but still held a place?
How will that affect things?

Image from Mr. Stadel.

Day 88b: More combinations

Blue, green, yellow, and red ... We seem to be all set.


What if I get three black markers out of the drawer?
How will that affect things?

Image from Mr. Stadel.

Day 88a: Combinations!

Blue, green, yellow, and red ... We seem to be all set.

Now, what about the black, purple, and orange ones?

And BROWN!

Image from Mr. Stadel.

Monday, April 14, 2014

Day 87: n!

It's a straightforward question today. Calculators are allowed for this question because we here do not feel that six-digit multiplication is worth the effort. I mean, we know you COULD do it, but that's what a tool is for, right?
For any confused students, this problem is not suggesting that 851 is special! That's factorial notation, n!, meaning multiply the integer n by all the positive integers less than n.  (Yeah, n must be a positive integer to begin with.)

For example, 6! = 6*5*4*3*2*1 = 720

For completeness, 0! = 1

Thanks to Darren, Right on the Left Coast, for this one.

Sunday, April 13, 2014

Day 86b: Flower Petals

What fraction of this is yellow?