Copyright © University of Cambridge. All rights reserved. The
picture above shows four equal weights on one side of the scale
and an apple on the other side. What can you say that is true
about the apple and the weights? If the apple weighs $180g$, how
heavy must one weight be? If the apple weighed $375g$, how heavy
would one weight be? If the apple was a giant one and weighed a
full kilo and the weights were each $250g$, what would the scale
look like? How do you know? Can you prove it?