Question 1159341
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Informally, using common sense -- as tutor @ikleyn says:<br>
The distance is the same; the time is 2/3 as much (20 minutes instead of 30). That means the speed has to be 3/2 as much.<br>
40kmh * 3/2 = 60kmh<br>
ANSWER: 60 km/hr<br>