Wilma and Betty ran a 100-meter race at top speed, and Wilma finished when Betty had 20 meters to go. They decided to run again, but this time Wilma gave Betty an advantage. Wilma's starting point was 20 meters behind the original starting point. Given that Wilma and Betty run at the same speeds as the previous race, how many meters will Betty be from the finish line when Wilma crosses it?

 Nov 15, 2020

I like this one....


If Betty  finishes 20m behind Wilma in the original 100m race.....her rate must be (80/100) = 4/5  of Wilma's


Thus, when Wilma runs 1 m , Betty runs (4/5) m


And in the second race, Wilma now runs 120 m


But Betty  only runs  (4/5)  of  this = (4/5) (120) =  96 m


So....Betty is  100 - 96  =  4m   from the finish line when Wilma crosses it



cool cool cool

 Nov 15, 2020
edited by CPhill  Nov 15, 2020

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