problem solving at Kaplan

[Steve Hwang]

Salesperson sold at average(arithmetic mean) of 28 widgets per week over 5 consecutive weeks. If every week, salesperson sold at least 14 widgets, what is teh greatest possible range of the number of widgets sold in any one week?
A. 28
B.35
C.56
D.70
E.84

[gmatrant]

Lets take the four weeks that have the least sales at 14 (since that is the min no that is sold each week) so 4*14 = 56. Now average for 5 weeks is 28, hence a total of 140 items are sold. So max in a week = 140 - 56 = 84.

The greatest possible range is 84 (maximum) - 14(minimum) = 70.

(PS :Initially I missed out on what was asked, so crucial for one's accuracy)