Question 1118007
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Use fractions instead of percentages when working problems like this.<br>
distance = rate times time<br>
If the distance is the same, then the rate (speed) and time are inversely proportional.  If the speed is lower, the time is longer by the same factor, and vice versa.<br>
Reducing the speed by 20% means the new speed is 80% of what it was.  80% as a fraction is 4/5.<br>
To cover the same distance at a rate 4/5 as fast, the time required is 5/4 as much.  5/4 as a percentage is 125%, which is 25% above 100%.  So the time increases by 25%.