after travelling a distance of 45 km . Aryan found that the 3/8 distance of his journey was still left. what was the length of his whole journey.

Aryan travelled 45 km.
He found that 3/8 distance was still left
Let the full journey  be 1.
              1-3/8 =8-3/8 = 5/8 =45km
Full journey = 45km * 8/5 = 360km /5 = 72km