Answer:
90π yd²
Step-by-step explanation:
the surface area of a cylinder is the sum of the lateral area and twice the aera of one end of the cylinder: π·d·l, where l represents the length of the cylinder. Here, the lateral surface area is π·6 yd·12 yd, or 72π yd².
The two ends add the following to the total surface area:
2·π·(d/2)², or 2π·d²/4.
Thus, the total surface area of the cyl. is
A = 2π·(6 yd)²/4 + 72π yd², or
A = 18π yd² + 72π yd² = 90π yd²
Note: Please check your source. L x W + 2pi ·r ^2 is incorrect.
Answer:

Step-by-step explanation:
Let
x ----> the average depth of the resulting layers of ash and rock
we know that
To find out the average depth, divide the cubic kilometers of molten rock by the area where all the ejected material fell.
so

Convert to meters
Remember that

so

Convert to mixed number

Answer:
11
Step-by-step explanation:
it says motor cycles combined with garbage so add both of them then subtract that from the bull dosers
motor =18
garbage=4
18+4=22
bulldosers=11
22-11= 11 more
The answer is 7. That's the answer