Hello, my friend,

 

Do it as follows :

 

1.    Normality, N = ( W_B *  1000 ) / ( E_B * V_S )

          Where symbols have there uaual meanings.

 

2.    N  = ( W_B *  1000 ) / ( E_B * [ M / Rho ] )          [ rho = density of solution ]

 

3.       N  = ( W_B *  1000 * Rho ) / ( E_B * M )                 [      M = Total mass of

                                                                                              solution ]

 

4.       Now, let the mass of solution be 100 gm, so, mass of KOH in solution

          is 30 gm.

 

5.       So, put the respective values in the formula and you will get rho.

 

Hope i am correct. But please do tell me if i am wrong.