Find the next number in the sequence

1, 2, 6, 21, 88, __?

What is black when you buy it, red when you use it, and gray when you throw it away?

Can you find out the missing number in the grid?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What 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?

Why do Chinese men eat more rice than Japanese men do ?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

What is the word or phrase?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

What word begins and ends with an E, but has only one letter?