Let point Q(5,4,–6) divide the line segment joining points P(3,2,–4) and R(9,8, –10) in the ratio k: 1Therefore, by section formula,(5,4,−6)=(k+1k(9)+3​,k+1k(8)+2​,k+1k(−10)−4​) ⇒k+19k+3​=5 ⇒9k+3=5k+5 ⇒4k=2 ⇒k=42​=21​ Thus, point Q divides PR in the ratio 1: 2.