Scott Woodbury-Stewart

GMAT OFFICIAL GUIDE PS – In a small snack shop, the average (arithmetic mean) revenue…

In a small snack shop, the average (arithmetic mean) revenue…

Solution:

This is a problem testing us on our knowledge of weighted averages. To solve, we can set up a weighted average equation:

(Revenue for first 6 days + Revenue for final 4 days)/10 days = 400

We know that the average revenue for the first 6 days was $360. We let r be the average daily revenue for the final four days, so we have

(360 x 6 + 4r)/10 = 400

2,160 + 4r = 4,000

4r = 1,840

r = 460

Answer: D