Respuesta :

The track increased 400m:


1600 - 1200 = 400



Use the rule of 3:


1200 - 100%

400 - x


(400 * 100) / 1200 = x

40 000 / 1200 = x

33,33... = x


The increase was of 33% aproximately.




Hope it helped,


Happy homework/ study/ exam!