PSAT Math Multiple-Choice Question 176: Answer and Explanation

Question: 176

If , where both m > 0 and n > 0, which of the following gives n in terms of m ?

• A.
• B.
• C.
• D.

Correct Answer: A

Explanation:

A

Difficulty: Medium

Category: Passport to Advanced Math/Exponents

Getting to the Answer: When you write an equation in terms of a specific variable, you are simply solving the equation for that variable. To do this, you'll need to use the property that raising a quantity to the one-fourth power is the same as taking its fourth root and that applying a negative exponent to a quantity is the same as writing its reciprocal. Rewrite the equation using these properties and then solve for n using inverse operations. Note that the inverse of taking a fourth root of a quantity is raising the quantity to the fourth power:

Choice (A) is correct.