A ruler has markings as shown below. Stefan uses this ruler to measure the length of a metal rod.

The punnett square is the device used to predict genetics.

The answer is c) tons

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it