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

There are three Athletes (John, Tarun and Harish) and their individual Coaches (Jacob, Meenaxi and Priyanka) standing on the shore.
No Coach trusts their Athlete to be near any other Coach unless they are also with them.
There is a boat that can hold a maximum of two persons.
How can the six people get across the river?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

There is something which you can be arrested for attempting but not for successfully completing.

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.

Can you calculate the total number of cans before distribution?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Name a key which is hardest to turn.

How many Watermelons are there in the below picture?