What is the next number in this matchsticks series riddle?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

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?

Name a key which is hardest to turn.

Your mother’s brother’s only brother-in-law is asleep on your couch. Who is asleep on your couch?

On a bus, there is a 26-year-old pregnant lady.
A 30-year-old policeman.
A 52-year-old random woman.
And the 65-year-old driver.

Who is the youngest?

John is found dead in a bare field. Nobody killed John,
John did not commit suicide.

Inspector Jacob found a bag just a few meters away from John which could save his life. What was in the bag?

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E