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

Correct option is D

Given:

Average on Sundays = 510 visitors

Average on other days = 240 visitors

Month has 30 days and starts on a Sunday

Formula Used:

Average per day = $$\frac{\text{Total visitors in month}}{30}$$​​

Solution:

In a 30-day month starting on Sunday, the number of Sundays = 5 (every 7th day starting from the 1st)

So:

Sundays = 5 days

Other days = 30 − 5 = 25 days

Visitors on Sundays = 5 × 510 = 2550

Visitors on other days = 25 × 240 = 6000

Total visitors = 2550 + 6000 = 8550

Average per day =$$\frac{8550}{30}$$​ = 285