We have, 2001=3.23.29 so, a=3,b=23,c=29 Since, direction ratios of a normal are b,c,a then the equation of plane is bx+cy+az+d=0 ⇒23x+29y+3z+d=0 It passes through (1,1,1) ∴23+29+3+d=0 ⇒55+d=0 ⇒d=−55 Thus, equation of the plane is 23x+29y+3z−55=0 ⇒23x+29y+3z=55