If the lines 1−x3=7y−142p=z−32 and 7−7x3p=y−x1=6−z5= and are at right angle, then the value of is
70/11
11/70
7/10
10/7
a1a2+b1b2+c1c2=0⇒−3(−3P7)+2P7+2(−5)=0⇒p=7011
Find the value of p so that the lines 1−x3=7y−142p=z−32 and 7−7x3p=y−51=6−z5 are at right angles