Returns the random number >=0 and <1.
* This function returns a number greater than or equal to zero and less than one.
* This function is volatile and will change everytime a cell on the worksheet is calculated.
* This function returns random values based on a uniform distribution.
* This function will update when the workbook is recalculated by pressing F9.
* This is one of the few functions that does not require any arguments.
* You must include the empty parentheses after the function name.
* The result from this function will change every time that the worksheet is calculated. If you have your calculation set to automatic then this will change every time you make an entry on the worksheet.
* To generate a random real number between a and b, use: RAND()*(b-a)+a
* If you want to generate a random number but don't want the number to change every time the cell is calculated, you can enter =RAND() in the formula bar, and press F9 to replace the formula with the value.
* In Excel 2010 the accuracy of this function was improved.
* You can use the RANDBETWEEN function to return a random number between two specified numbers.
* For the Microsoft documentation refer to support.office.com
4 - Returns a random number between 10 and 20.