The Hunting Dog
Two brothers go hunting separately, but in the same area. Having only one dog, they toss a coin to see which one the dog accompanies. After a while, both are on higher ground a half mile apart, and they spot each other. They begin to walk toward each other at 2.5 mph. The dog also spots the other brother and runs ahead to meet him, at 9 mph. The dog runs back and forth between the two brothers until they meet.
How far does the dog run?
How far does the dog run?
posted by Zaux at
7:22 AM
7 Comments:
Two guys 0.5 miles apart
they walk to each other at 2.5 mph
0.5 miles / 5 mph = 0.1 hours
The dog runs 9 mph, he will cover
9*0.1 = 0.9 miles
"They begin to walk toward each other at 2.5 mph. "
If this mean "each" moves at 2.5 then the total would be 5 mph.
That's what I assumed you mean,
but it could mean there combined speed was 2.5 mph
If so, then double the dogs distance. 1.8 miles
Ragknot ... my intent was that tey walk towards each other at a combined 2.5mph rather than a combined 5 mph.
.9 miles, as you stated, is the correct distance
Zaux...eh?
As Ragknot says
Combined speed 2.5mph - 1.8miles
Combined Speed 5mph - 0.9miles
This is a very old puzzle ... I first read it in 1983 in Martin Gardner's "Wheels, Life, and other Mathematical Amusements", but it's a lot older than that of course.
The interesting problem is the one where you start with the brothers together and try to figure out where the dog ends up.
The dog doesn't travel any where it just runs up and down in the end its in the same place. because the brothers meet lol.
Sorry Anonymous. That doesn't work at all. The brothers were half a mile apart, the met half way, the dog was with one of the brothers, so it's changed it's position by 1/4 mile. Besides, the question asked how far the dog ran; in my view, that's completely unambiguous.
I bet that if you went somewhere a 100 miles away, then when you'd got back you'd say that you'd travelled 200 miles, especially if you were doing your company expenses claim. Am I right, or am I right, or am I right?
Post a Comment
Links to this post:
Create a Link
<< Home