Hi nkmungila1
Since the average attendance on a Sunday is different from that of any other day, we clearly have to figure out the number of Sundays that we're dealing with (out of the 30 total days). As such, it would likely help to 'draw out' a quick calendar in 7-day increments:
Sun - Sat = 7 days
Sun --> 14 total days
Sun --> 21 total days
Sun --> 28 total days
Sun, Mon --> 30 total days
Thus, we have 5 Sundays and 25 non-Sundays. This is a ratio of 1 to 5, so we can calculate the average attendance using that ratio:
(510 + (5)(240))/6 =
(510 + 1200)/6 =
1710/6 =
285
Final Answer: D
GMAT assassins aren't born, they're made,
Rich