729. multiple 9 times 9 then 81 times 9 and you get D
Answer:
r = C / (2pie)
Step-by-step explanation:
C = 2pie x r
divide both sides by 2pie to isolate r
C / (2pie) = r
r = C / (2pie)
That's a 33% increase.
I calculated this using the formula:

Where n = the new value (16 in your question), o = the old value (12 in your question) and the result is outputted as a percent increase. You can check that this is correct by finding 33% of 12, adding the result to 12, and checking that the result equals your "new" number.
Note that 33% is only an approximation as your question requires a number rounded to the nearest whole.
The answer is 1 19/80 or 1.2375.
Hope this helps!