Can you replace the question mark with the correct number?

What does this below rebus puzzle mean?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Which digit occurred maximum times between the number 1 and 1000?

What is harder to catch the faster you run?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

What is next number in the pattern below:

131 517 192 123 ?

A spy was in Canada trying to steal insider information on how to set up new Maple Syrup factories in their country. He was introduced to the operations manager of the biggest factory in Canada. However, the manager was suspicious and decided to test him with a question before he trusted him. So he asked, “What would you be sure to find in the middle of Toronto?” The spy thought fast and came up with an answer for the manager. What was his answer?