Amit starts from a point A and walks to another points B and then returns from B to A by his car and thus takes a total time of 6 hours and 45 min. If he had driven both ways in his car, he would have taken 2 hours less. How long would it take for him to walk both ways ?

Let the distance be x km
(Time taken to walk x km) + (Time taken to drive x km) = $$\frac{27}{4}$$ hrs
⇒ (Time taken to walk 2x km) + (Time taken to drive 2x km) = $$\frac{27}{2}$$ hrs
But time taken to drive 2x km = $$\frac{19}{4}$$ hrs
∴ Time taken to walk 2x km :
= $$\frac{27}{2}$$ - $$\frac{19}{4}$$
= $$\frac{35}{4}$$ hrs
= 8 hrs 45 min