Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

What is the fastest way to double your money?

Complete the table series riddle by finding the number that can replace "??".

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

Find the next number in the series.
1 10 24 43 67 ?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

The Little ant seems to be always confused. Do you know why?

I am a mother. However, I never give birth.

I am a father. However, I never nurse my children.

Wandering is not possible for me, but standing still happens occurs rarely.

Who am I?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?