GMAT Problem Solving (PS) | Re: A car traveling at a certain constant speed takes 5 seconds longer to

Car travelling at 80kmph covers 1 km in (1/80) hrs =\(\frac{60*60}{80}\) = 45 sec.

The other car takes 5 sec more. So the time taken by that car is 50 sec. Distance is 1 Km. So its speed is (1 Km / 50 sec) or

\(\frac{60*60}{50}\) = 72 kmph

B is the answer.
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