Why is a river so rich ?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Spot 5 differences in two Christmas tree below:

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

Two natural numbers have a sum of less than 100 and are greater than one.

John knows the product of the numbers and Jacob knows the sum of numbers.

The following conversation takes place between them:
John: 'I am not aware of those numbers.'
Jacob: 'I knew you wouldn't be. I am not aware myself.'
John: 'Now I know them!'
Jacob: 'Now I know them, too!'

What are the two numbers?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?