Digital PSAT Math Practice Question 251: Answer and Explanation

Question: 251

Which of the following expressions would be equivalent to the diameter of the sphere portrayed above, with a radius of r and volume V?

• A.
• B. πr³
• C.
• D.

Correct Answer: A

Explanation:

(A) The volume of a sphere is given by the formula . The diameter is twice the radius, so you can solve for the radius and multiply by 2. To solve for r, first divide both sides by :

. To solve for r, take the cube root of both sides:

. Multiply this by 2 to get an expression for the diameter:

, answer (A).