Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Paltu Sen
there is no short cut method....but in this problem you can split the third column in two columns and then find the determinants separately....and sum up the values. to find the determinant of order 3x3, you can follow vedic math tricks