Can you replace the question mark with the correct number?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

I travel all around the world but always stay in the corner. What am I?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

John is the son of Jacob.
So,
Jacob is the_____of John's father?

There is a bag which have 21 blue balls and 23 red balls. You also have 22 red balls outside the bag. Randomly remove two balls from the bag. * If they are of different colors, put the blue one back in the bag. * If they are the same colour, take them out and put a red ball back in the bag. Repeat this until only one ball remains in the bag. What is the color of the sole ball left in the bag ?

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?

If six children and two dogs were under an umbrella, how come none of them got wet?