Answer:
c. 300%
Explanation:
In order to solve this problem you just have to divide the bigger polyhedral by the smaller polyhedral:

As this is equal to 3, you know that the bigger polyhedral is 3 times bigger than the smaller polyhedral so now you just make a rule of three, if an object that is 100% bigger than other is 1 time bigger, what would be the percentage of an object that is 3 times bigger?

Once you clear the X the equation would look like this:

