Eight of us go fourth, not back, to protect our king from an attack. What are we?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Count the number of triangles in the picture below:

When 99 is considered higher than 100?

People put me on the table and cut me but do not eat me. What am I?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

What Time Should the last watch show in the below figure?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.