What does this mathematical rebus means ?

Find the smallest sentence with all the English alphabet.

What is more useful when it is broken?

What has a ring but no finger?

People make me, save me, change me, raise me. What am I?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Why is it very easy to weigh a fish?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?

I am the fastest animal but cannot climb the tree. What am I?

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kittens, cats, sacks, wives. How many were going to St. Ives?