A Question of Distance

                  It was a beautiful sunny morning. The air was fresh and a mild wind was blowing against my wind screen. I was- driving from Bangalore to Brindavan Gardens. It took me I hour and 30 minutes to complete the journey.

  After lunch I returned to Bangalore, I drove for 90 minutes. How do you explain it?

Answer:      There is nothing to explain here. The driving time there and back is absolutely the same because 90 minutes and 1 hour and 30 minutes is one and the same thing. 
                    This problem is meant for inattentive readers who may think that there is some difference between 90 minutes and 1 hour 30 minutes.