A library has an average of 510 visitors on Sunday and 240 on other days. The average number of visitors per day in a month of 30 days beginning with a Sunday is___________?

A. 250
B. 276
C. 280
D. 285

Explanation:

Since the month begins with a Sunday, so there will be five Sundays in the month.

Required average = [(510 * 5) + (240 * 25)]/30 = 8550/30 = 285