A certain lighthouse is a tall thin cylinder of brick, with a light ch

Here we go,

Total Surface Area of Cylinder = 2πr(h+r)

St1 and St2 provides the required info.

Option C is correct

MAGOOSH OFFICIAL SOLUTION:

The lighthouse is essentially a cylinder, and the area that needs to be painted is the lateral surface area. We would need both r and h to calculate this.

Statement #1 tells us diameter = 28, which means radius = 14. We know the radius, but not the height. Statement #1 by itself is insufficient.

In Statement #2, the 274 steps go from the very bottom to the very top of the cylinder in question. We know each step is 8 inches, so the total height traversed by the steps is 274*8 in. We would have to change that result from inches to feet, but essentially, with this piece of information, we have the height. We know the height, but not the radius. Statement #2 by itself is insufficient.

Combined. Statement #1 gives us the radius, statement #2 gives us the height, and we’re in business! We now have enough information to calculate the lateral surface area. Combined, the statements are sufficient.

Answer = C.

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#1
we have radius but no info of height ; insufficient
#2
we have height but no info of radius
insufficient
from 1 &2
we can find both vol and TSA
sufficient
IMO C

I UNDERSTAND WHY PEOPLE CHOSE TO MARK C AS THE ANSWER, BUT

THE BRICK SIDING IS ON BOTH SIDES OF LIGHTHOUSE, WHAT THEY ARE ASKING US IS WHATS THE TOTAL SURFACE AREA OF THE BRICK SIDING.
WHY HAVE WE NOT CONSIDERED THE INNER DIAMETER?

BECAUSE IT DOESN'T SPECIFY HOW THE STAIRS SYNC TO THE WALLS. THEY CAN BE SEPARATE

Just an observation. A brick portion = area between outer circle and inner circle of the concentric circle formed, right?

That needs to be true for us to use A.

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