Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

I’m tall when I’m young, and I’m short when I’m old. What am I?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

John went to meet his friend Jacob, but when he was about to reach the main gate, John notices that Jacob had a mighty dog who was fastened to the tree. The chain is long enough that it allows the dog to reach the main gate.

How can the John reach the main gate?

Why is the longest human nose just 11 inches?

Why is it very easy to weigh a fish?

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

In the given picture, you can find two letters missing. When two particular letters are placed in the missing spots, you get an eight-letter word while reading in the anti-clockwise direction. Can you find out the missing letters and the missing word eventually?