What runs around the whole yard without moving?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

How many bananas can you eat if your stomach is empty?

Which tank will fill first?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Solve the riddle below:

If a Chicken says, 'All chickens are liars" is the chicken telling the truth?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.