During an athletics training session, Jenny runs 12 laps of a 400-meter track. She wants to run a total of 8 km. How many more laps does she need to run?

1 Answer
Oct 31, 2016

She must run another #8# laps more.

Explanation:

Each turn gives Jenni, she travels a distance of 400 m. If initially she had run #12# laps that means she had run a distance of:

#12 laps times 400 m//lap = 4800 m# .

Jenny wants to run a total distance of #8 km#, i.e.:

#8 times 1000 = 8000 m# .

Therefore:

#8000 m - 4800 m = 3200 m#

are still missing to go. If we divide the distance so it runs at every turn, we have

#3200 // 400 = 8# laps,

which is the number of turns that Jenny remains to run.