A new cell phone plan is offering pricing based on average m

[BTGmoderatorDC]

A new cell phone plan is offering pricing based on average monthly use. Brandon and Jodie are comparing their average use to determine the best plan for them. Brandon's average monthly usage in 2001 was q minutes. Was this less than, greater than, or equal to Jodie's 2001 average monthly usage, in minutes?

(1) From January to August 2001, Jodie's average monthly usage was 1.5q minutes.
(2) From April to December 2001, Jodie's average monthly usage was 1.5q minutes.

OA B

Source: Manhattan Prep

[Ian Stewart]

If Brandon averaged q minutes per month, his total usage for the year was 12q minutes.

From Statement 1, we know for 8 months Jodie averaged 1.5q minutes per month, so during those 8 months, she used (8)(1.5q) = 12q minutes in total. She might have used zero minutes the rest of the year, in which case her usage equaled Brandon's, or she might have used some additional minutes, and her total usage (and thus average monthly usage) might have exceeded Brandon's. So Statement 1 is not sufficient.

From Statement 2 we know for 9 months Jodie averaged 1.5q minutes per month, so she used a total of (9)(1.5q) = 13.5q minutes during those months, and her usage must have exceeded Brandon's total of 12q minutes, regardless of what she did the rest of the year. So Statement 2 is sufficient and the answer is B.

[deloitte247]

Statement 1
From January to December 2001, Jodie's monthly average usage was 1.5 q minutes.
The total usage from January to August is 1.5q *6 = 12q minutes .
monthly average = 12q/12 = 1q minutes
If she use at least 1 minute from September to December, then her average monthly usage will be greater than that of Brandon. But if she didn't use any minute from September to December then her average usage will be equal to that of Brandon.
Statement 1 is INSUFFICIENT.

Statement 2 From April to December 2001, Jodie's average monthly usage was 1.5q min.
Total monthly usage from April to December is 1.5q*9 = 13.5q minutes
monthly average = 13.5q /12 = 1.125q minutes

Even if she didn't use any minute from January to March. her average monthly usage will still be greater than that of Brandon.

Statement 2 is SUFFICIENT. $$Answer\ is\ Option\ B$$