Explanation In a month of 30 days beginning with a Sunday, there will be 4 complete weeks and another two days which will be Sunday and Monday.
Hence there will be 5 Sundays and 25 other days in a month of 30 days beginning with a Sunday
Average visitors on Sundays = 510
Total visitors of 5 Sundays = 510 × 5
Average visitors on other days = 240
Total visitors of other 25 days = 240 × 25
Total visitors = (510 × 5) + (240 × 25)
Total days = 30
Average number of visitors per day
= [(510×5)+(240×25)]/30
= [(51×5)+(24×25)]3
= (17×5)+(8×25) = 85+200 = 285.