In. 6 Its a demand determined economy, supply technology changed but demand didn't so. Y remains same in 1st part. But for the same Y we need half L. So Unemployment increases.
Similarly the 2nd part.
19. (c) Perform these elementary row operations to the given matrix to reduce it into row-reduced matrix form : (i) R3' = R3 – R2 + R4 ,
(ii) R2 is interchanged by R4,
(iii) R4' = R4 - R3 ,
Then R4 of the given matrix will vanish. So, rank is 3.