Public forum discussion.
23 Jun 2014
Parade Magazine (usually included in most newspaper's Sunday edition) carries a column by Marilyn vos Savant. She is supposed to have an IQ over 190 but she blew it on Sunday. Here is the problem:
Brad and Angie, working together, can do a project in 6 hours. If they do it separately Brad would take 4 more hours and Angie. How long would it take each of them working separately? Her answer was truly junk math. When I queried my circle of friends (actually my fellow mountain bikers) only two got the right answer.
Let's see if my fellow Little Golemers do any better.

23 Jun 2014
I suppose you meant: If they do it separately Brad would take 4 more hours than Angie.
23 Jun 2014
Yes, mtbikesman is supposed to have a Twixt PP rating over 2060 but he blew it with his poor grammar in this post. :)
23 Jun 2014
I got that Angie would take 10.32 hours and Brad would take 14.32 hours (approximately).
23 Jun 2014
I blame it all on my keyboard. I hit the keys correctly but somehow my keyboard screwed it up.
And my Twixt rating is about to tumble. I am losing a number of games as of now.

23 Jun 2014
Yes, we all have our moments... yesterday I lost a 9x9 go game to a near-beginner.
Was my answer right?
23 Jun 2014
You got the right answer. The wrong answer published in the magazine was 10 and 14 based of some pretty junk math.
p.s. I don't even know how to play Go. Twixt is the only game I am any good at.
23 Jun 2014
The correct answer is: A took 1 second and B 4 hours + 1 second. Together it takes 6 hours of A explaining the problem to B while B stares at A's breast. By themselves, A types the two letter answer she already knows in one second and B googles it but gets distracted by some videos, friends and reading A's facebook profile.
Since when does humans "working together in a project" means progressing at constant independent rate. Who created the problem, a robot?
23 Jun 2014
Yes, there are implicit and unwarranted assumptions that this project, whatever it is, is simple enough that Brad and Angie could spend zero time agreeing on division of labor, and neither will need the results the other comes up with before proceeding full tilt, etc.
But if you accept this absurdity, Brad would take 8 + 2*(sqrt(10)) hours and Angie would take 4 + 2*(sqrt(10)) hours.
23 Jun 2014
Amazing that you are all smarter than Marilyn.
And to answer David J., they were filling a swimming pool with hoses. Simple enough task for you?
24 Jun 2014
Just what I wanted, a swimming pool full of hoses!
Thanks Angie and Brad!
24 Jun 2014
There's another classic question in a similar vein. Suppose I drive to my friend's house at 30 miles per hour, and later on I drive back home at 20 miles per hour along the same route. What was my average speed on the road? (It's not 25 miles per hour.)
24 Jun 2014
It would be 24 mph allowing 1 nanosecond to the bathroom
24 Jun 2014
24 Jun 2014
"And to answer David J., they were filling a swimming pool with hoses. Simple enough task for you?"
Only if the rates of flow are constant and independent of each other. That means they probably can't both be connected to the same source. And why couldn't Brad just turn on both hoses? Is he some kind of doofus dorfball or wot? Furthermore I don't like his trousers.
24 Jun 2014
The hoses came from each other homes and they lived next to each other. And yes, Brad and Angie are indeed morons.
25 Jun 2014
Didn't Brad and Angie have a bunch of adopted kids? Make them fill up the pool. Earn that movie star allowance.