Hi, wonder if anyone can help me with a question that has been bugging me!

A recipe for a 7.5 inch square-based iced cake is scaled up the cake to make a cake of the same shape but with a 10 inch square-based cake.

How could i work out roughly:

1. Volume of 10 inch over 7.5 inch

2. How much more flour is needed

3. How much more icing is needed

Thanks for any help!

Matt