Statement-I      A symbol that can be taken various numerical values is called a variable.

Statement-II      A symbol which has a fixed value is called a constant.

STATEMENT_I  : A symbol which can take various numerical values is called variable

Example : $a,b,c,d\mathrm{.......},x,y,z$  English alphabet letters.

$\alpha ,\beta ,\gamma ,\delta ,\theta \mathrm{......}$   Greek letters. 

STATEMENT_II : A symbol which has a fixed value is called  constant 

Example : $1,2,3,4,5,\mathrm{6......}$