Time and distance

Question

Kate exercises on a treadmill for exactly 1hr,some of the time running 7mph and some time walking at 3mph.The treadmill registers that she has covered 6.6 miles.How much further must she run if she wants to run a total of 7 miles , not counting the distances she walked.

Answer 1

Hi Sumathi,

The distance formula is distance = rate X time

d = rt

Let t = time running          

Let 1 - t = time walking

distance covered running = 7t

distance covered walking = 3(1-t) = 3-3t

total distance = 7t + 3 - 3t = 6.6

4t + 3 = 6.6

       4t = 3.6

         t = .9 hours = 54 minutes

 

distance walked = 3(1-t) =3(1-.9) = .3 miles

6.6 - .3 = 6.3

7 - 6.3 = .7 miles    amount she still needs to run