JEE Main 202116 Mar, Morning shiftMathematicsHardThree Dimensional Geometry249× since 2002
Let the position vectors of two points P and Q be 3 + 2 and + 2 4, respectively. Let R and S be two points such that the direction ratios of lines PR and QS are (4, 1, 2) and (2, 1, 2), respectively. Let lines PR and QS intersect at T. If the vector is perpendicular to both and and the length of vector is units, then the modulus of a position vector of A is :