What is the next number in this matchsticks series riddle?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

Can you replace the question mark with the correct number?

What is the word or phrase?

If an electric train is travelling south, then which way is the smoke going?

A woman shoots her husband.

Then she holds him under water for over 5 minutes.

Finally, she hangs him.

But 5 minutes later they both go out together and enjoy a wonderful dinner together.

How can this be?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

How many times can you subtract the number two from the number fifty?

Rearrange the letters in "new door" to make one word.

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13