If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

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

which number am I?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

What goes up but never comes down?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

I am quite hot but become too cold if you remove the first two letters. What am I?