Question

51 meters to 68 meters

Answer 1

It would take 17 meters to travel that far...

Answer 2

This is an equation on percent of increase. 
The equation for this type of question is
new amount (68)-old amount (51)/original amount (51)
= 17/51
=0.333333333 (change that to a percent)
= 0.333333333*100
= 33%