What is the volume of the frustum? a. 258.47 b. 503.77 c. 588 d. 147

V = 1/3 πh(R^2 +r^2 + R*r)
V = 1/3 (3.14)(14) (4.2^2 + 2.5^2 + 4.2 * 2.5)
V = 1/3 (3.14)(14) (17.64 + 6.25 + 10.5)
V = 1/3 (3.14)(14) (34.39)
V = 503.93

Because i'm using π = 3.14

So answer is B. 503.77

The formula for the volume of a frustum of a cone is
  V = (1/3)π·(R² + r² +r·R)·h
where R and r are the radii of the circular faces.

For your figure, R = 4.2, r = 2.5, h = 14. Filling in the given numbers, you have
  V = (π/3)(4.2² +2.5² +4.2·2.5)·14 ≈ 504.18

It looks like the appropriate choice is probably
  B. 503.77


Sometimes the answers to these problems are figured using incorrect rounding and inappropriate values of π. It looks like this answer key was simply miscalculated.

Hope i can you!