I am in the sky but also in the ground. When you study me, no matter how long, I will always end with an f. I may be in your yard but not in your house. What am I?
Two bikes are traveling toward each other at a constant speed of 10 mph. When the bikes are 20 miles apart, a bee flies from the front wheel of one of the bikes toward the other bike at a constant speed of 25 mph. As soon as it reaches the front wheel of the other bike, it immediately turns around and flies at 25 mph toward the first bike. It continues this pattern until the two bikes smush the bee between the two front tires.
The easiest way to think about this is to consider the time. The bikes will take 1 hour to touch, given that they start 20 miles apart and are each traveling toward each other at 10 mph.
Therefore the bee is buzzing back and forth at 25 mph for 1 hour.
I’m up and down and round about, yet all the world can’t find me out. Though thousands have employed their leisure, they never yet could find my measure. I’m found in almost every garden, In a compass or a farden. There’s neither chariot coach nor mill may move one inch except I will.
There is an abandoned aquarium in an empty house. The aquarium has three large fish and three small fish. But after a week, one large fish and two small fish die.
A scent or smell. A scent is important to both humans and animals and both search for scents (for different reasons). A scent travels through the air to benefit humans and animals, again, for different reasons.
Special thanks to Vavessa for the answer to this one.