A man walk a certain distance and rides back in 4 hours 30 minutes. He could ride both ways in 3 hours. The time required by the man to walk both ways is :

Answer: Option D

Time taken to ride one way :
= $$\frac{3}{2}$$
= 1.5 hrs
Time taken to walk one way :
= 4.5 - 1.5
= 3 hrs
Time taken to walk both way :
= 3 × 2
= 6 hours