9514 1404 393
Answer:
9 minutes
Step-by-step explanation:
In terms of hours, the travel times are ...
time = distance/speed
Expected time
te = (30 mi)/(50 mi/h) = 3/5 h = 36 minutes
Actual time
ta = (30 mi)/(40 mi/h) = 3/4 h = 45 minutes
Then the extra time taken is ...
(45 -36) min = 9 minutes
The journey took 9 minutes longer than expected.