The answer is the number will have to be less than 11 which means that it is a. 9
sorry if it is incorrect.
I just did this I’m gonna have my friend come and answer this for u
we know that
The formula of the surface area of the cone is equal to

where
SA is the surface area
r is the radius of the cone
l is the slant height
in this problem we have

Solve the formula for l

substitute the values

therefore
<u>the answer is</u>
The slant height is 
First you raise the expressions in the parentheses to their powers. Then multiply the two expressions together. You get to see multiplying exponents (raising a power to a power) and adding exponents (multiplying same bases).
The answer to your question is...
60 times more than a minute!