Answer:
Doug wins. He finishes in 1.38 minutes. Bert takes 1.51 minutes.
Step-by-step explanation:
Each city block is a square 1/16 mile by 1/16 mile.
From 6th Av and L Street to 10th Av and E Street, they need to go 4 avenues and 7 streets over. These two distances along blocks are the legs of a right triangle. The right triangle has legs of length 4 * 1/16 mile and 7 * 1/16 mile.
leg1 = 4 * 1/16 mile = 0.25 mile
leg2 = 7 * 1.16 mile = 0.4375 mile
The hypotenuse of the right triangle can be calculated by the Pythagorean theorem.
a^2 + b^2 = c^2
(0.25 mile)^2 + (0.4375 mile)^2 = c^2
c = 0.50389
The direct distance from one corner to the other is 0.50389 miles.
The bird travels this distance since the bird can fly above the streets.
The dog has to travel along the legs of right triangle by running in the streets and avenues. The dog travels 0.25 mile + 0.4375 mile = 0.6875 miles
Now we need to see what takes less time:
Bird: distance of 0.50389 miles at 20 mph, or
Dog: distance of 0.6875 miles at 30 mph
We start with the formula for speed:
speed = distance/time
s = dt
Now we solve it for time:
st = d
t = d/s
Time equals distance divided by speed.
Now we find the times for the bird and for the dog.
Bird:
t = d/s = (0.50389 mi)/(20 mi/h) = 0.02519 hours = 1.51 minutes
Dog:
t = d/s = (0.6875 mi)/(30 mi/h) = 0.0229 hours = 1.38 minutes
The bird takes 1.51 minutes, and the dog takes 1.38 minutes.
The dog takes less time to get there, so the dog wins.
