What does 27 1/2 x 5 =?

Question

I need help with my thinking skills class. the teacher told us to find how far a rock wall is if you hear your echo 15 seconds later.

Answer 1

What does 27 1/2 x 5 =?
I need help with my thinking skills class. the teacher told us to find how far a rock wall is if you hear your echo 15 seconds later.

27.5 * 5 = 137.5

As for your second question, the speed of sound is about 1,126 ft/sec.
If it takes 15 seconds for the sound to make the round trip, the time
for the sound to travel one way is 7.5 seconds.
In 7.5 seconds, sound would travel 7.5 sec * 1,126 ft/sec = 8,445 ft.
There are 5,280 ft in a mile, so the wall is 8,445 ft / (5,280 ft/mi) = 1.599 mi away