Math Chapter Wise Matrices And Determinants English MCQ UP PCS (Pre) 2009 Q.If 1 2 3 A 4 2 5 − = − and 2 3 B 4 5 2 1 = then AAB, BA exist and are equal. BAB, BA exist, but they are not equal CAB exists and BA does not exist DAB does not exist and BA exists Show answer Correct answer: AB, BA exist, but they are not equal