Answer:
5: 6
Step-by-step explanation:
becuase it was basically 100:120 but divide it by 20 and thats how you get 5;6
If a function is defined as

where both
are continuous functions, then
is also continuous where defined, i.e. where 
So, in your case, this function is continous everywhere, except where

To solve this equation, we can use the formula 
It means that, if the leading terms is 1, then the x coefficient is the opposite of the sum of the roots, and the constant term is the product of the roots.
So, we're looking for two terms whose sum is 7, and whose product is 12. These numbers are easily found to be 3 and 4.
So, this function is continuous for every real number different than 3 or 4.
Area of a circle = Pi x raduis^2? so the answer is 254.47mm^2