Question 551491
subbing in we get 
137 1/2 km=55 km/h * t
divide both sides by 55km/h
137 1/2 km/55 km/h=t

Now we could simply put 137 1/2 / 55 in on a calculator but let's say you aren't allowed to use one. Let's use estimation. 137 1/2 divided by 55 should give me more than 2 since 110/55=2  It should give me less than three since 165/55=3. 137 is always between those, so I'm expecting my answer to be 2 1/2 h