Bob challenges Jenny to a 100 meter race. Jenny agrees if she gets a 20 meter head start. Jenny’s average is 12 seconds while Bob’s is 10 seconds.

Question

Answers fast with explanation of work please :) (both kept a constant speed)

Answer 1

Hi Julie -  who wins this race? Let's see!  

 

Bob's speed is 10m per second (100 meters/10 seconds)

 

Jenny's speed is 8.3m per second (100m/12s)

 

Jenny better finish the race(100m -20m = 80m) in less than 10 seconds.  Can she do it?

 

80m/8.3m per second = 9.6 seconds

 

jenny wins the race by .4 seconds (10 - 9.6)

 

hooray! Go Jenny!