A pencil consists of a cone stacked on top of a cylinder. The diameter of the cylindrical base of the pencil is 10 mm and the height of the cylinder is 70 mm, while the height of the cone is 12 mm. Calculate the surface area of the pencil. Leave your answer in terms of π. 835π sq. mm. 790π sq. mm. 785π sq. mm. 1820π sq. mm.

Step-by-step explanation:

A lead pencil consists of a cylinder of wood with a solid cylinder of graphite filled in the interior. The diameter of at the pencil is 7 mm and the diameter of the graphite is 1 mm. If the length of the pencil is 14 cm, find the volume of the wood and that of the graphite.

answer: 21$

step-by-step explanation:

$42 / $14 = 3   (ratio 3: 1)

$7 x 3 = $21