Question

this is the last one ok

Answer 1

Sorry it took so long, had to go find my scientific calculator :)

The correct answer is 241.5 cm. 

Hope this helped again Richard!!

Answer 2

The answer is 241.5.  You need to divide it by the first part of the scale(2 cm) and multiply by the second.  For example, when it says 18 cm, you divide by 2, and then multiply by 7.  You get 63.  Do this to all the numbers and get the sum.