Like this kind of problem, my primary school math teacher said, draw a line segment for the distance problem, as shown in the figure:

40 is time, 4/5 means: 40 minutes has covered four-fifths of the whole journey, so: 40? 4/5 is the time required for the whole journey, so the wrong unit of the first step should be minutes.

The second step is correct.

Conclusion: It will be very simple to draw a line segment to solve this problem.