Answer:
4
Step-by-step explanation:
400 - 200 = 600.
282 - etc. etc.
this is my answer but you need to check with your teacher
Answer:
Option B is correct = 
Step-by-step explanation:
<u>The complete question is:</u> Which of the following options have the same value as 30% of 81?
Group of choices is:
(A) 
(B) 
(C) 
(D) 
(E)
Now, the expression given to us is 30% of 81.
Simplifying the above expression we get;
30% of 81 =
=
= 
Now, we will solve each of the given options and then see which option matches with our calculation.
Option (A) is given;
= 
This doesn't match with our answer, so this option is not correct.
Option (B) is given;
<u><em>This matches with our answer, so this option is correct.</em></u>
Option (C) is given;
This doesn't match with our answer, so this option is not correct.
Option (D) is given;
= 
This doesn't match with our answer, so this option is not correct.
Option (E) is given;
This doesn't match with our answer, so this option is not correct.
Step-by-step explanation:
the lateral area of the cone is, well, the lateral area.
the total surface area of the cone is the lateral area plus the area of base circle.
so, the difference between both is the area of the base circle :
120pi - 70pi = 50pi
the area of a circle is
pi×radius²
and that is in our case
pi×radius² = 50pi
radius² = 50
radius = sqrt(50) = 7.071067812... ≈ 7.1 units
therefore, C is the right answer.