Question 16
Australia has rectangular currency notes for \$5, \$10, \$20, \$50 and \$100. These notes are all 65 mm wide but each note is 7 mm longer than the note of the next lowest value, so the \$10 note is 7 mm longer than the \$5 note, and so on.
The difference in area, in square millimetres, between the \$10 note and the \$100 note is
The difference in area, in square millimetres, between the \$10 note and the \$100 note is