Answer:
If four people can repair four bicycles in four hours, how many bicycles can eight people repair in eight hours?
I always run but never walk, often murmur, never talk, have a bed but never sleep, have a mouth but never eat. Who am I?
I cannot be used until I have been broken. What am I?
What has a spine, tail, and leash but isn't a dog?
Which friend of a witch eats the fastest?
I appear in the morning. But am always there. You can never see me. Though I am everywhere. By night I am gone, though I sometimes never was. Nothing can defeat me. But I am easily gone.