2, 3, 5, 9, 17, _ What is the next number in the sequence?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

In the four images below, can you find the odd one out?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

I am 5 letters long.
My first two tell you who I am
My first 3 could be a medicine
My last three reversed could be a young boy.
My 4th, 3rd and 2nd in that order could be a fruit drink.
If you have me you may hang me round your neck
WHAT AM I ?

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?