The direction ratios of the line joining the points Ax1,y1,z1and Bx1,y1,z1 isx2−x1,y2−y1,z2−z1The direction ratios of the line joining the points P1,2,5,Q2,4,7 is 1,2,2Direction cosines are 11+4+4,21+4+4,21+4+4=13,23,23