Q.

Let the line L pass through (1, 1, 1) and intersect the lines x12=y+13=z14 and x31=y42=z1. Then which of the following points lies on the line L       [2025]

1 (10, –29, –50)  
2 (4, 22, 7)  
3 (7, 15, 13)  
4 (5, 4, 3)  

Ans.

(3)

Equation of line L passes through (1, 1, 1) is L:x1a=y1b=z1c, where a, b, c are direction ratios.

Let L1:x12=y+13=z14=λ (say)

Any point on L1 be A(2λ+1,3λ1,4λ+1)

Let L2:x31=y42=z1=μ (say)

Any point on L2 be B(μ+3,2μ+4,μ)

Direction ratio of L be : <2λ,3λ2,4λ> or <μ+2,2μ+3,μ1>

Now, 2λμ+2=3λ22μ+3=4λμ1  λ=65 and μ=5

  <a,b,c><3,7,6> or <3,7,6>

  L:x13=y17=z16

Hence, (7, 15, 13) lies on the line.