Solutions

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Question

The cost of a certain phone call was $0.75 for the first 3 minutes and $0.20 for each additional minute after the first 3 minutes. Did the phone call last longer than 15 minutes?

I. The cost of the phone call was less than $4.16

II. The cost of the phone call was greater than $3.35


 

Option A:

Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked.

Option B:

Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.

Option C:

BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.

Option D:

EACH statement ALONE is sufficient to answer the question asked.

Option E:

Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

Difficulty Level

Hard

Solution

Option B is the correct answer.


Option Analysis

According to the above the cost for n minutes, where n>3, is 75+(n−3)∗20=20n+15 cents. W need to find whether n>15. The cost for 15 minutes is 20n+15=20∗15+15=315 cents, so we need to find whether the cost is greater than 315 cents.

Statement I is insufficient: The cost of the phone call was less than $4.16. Not sufficient.

Statement II is sufficient: The cost of the phone call was greater than $3.35. Sufficient