If the determinant of the 3 × 3 matrix given by | (1+a)2 (1+2a)2 (1+3a)2 | | (2+a)2 (2+2a)2 (2+3a)2 | | (3+a)2 (3+2a)2 (3+3a)2 | = -648a, then the value of a is:

Who among the following founded the 'Forward Bloc'?

Which of the following statements regarding the Harappan Civilization is NOT correct?

Which ruler is generally credited with unifying much of Northern India under a single empire for the first time?