Quantitative Aptitude - Arithmetic Ability Questions

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 : 

Solve the following

24 / (20 - 12 / 3 x 8) = ?

Select the option that can replace the question mark (?) in the following equation.

0.23 - 0.130.2 + 0.12

Which of the following statement(s) is/are TRUE?

I. √5 + √5 > √7 + √3
II. √6 + √7 > √8 + √5
III. √3 + √9 > √6 + √6

The area of a circle is 616 sq.cm. Find its radius (in cm).

The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is :

Given w = -2, x = 3, y = 0 & z = -1/2, find the value of w2(z2 + y2)

Simplify : (27)-23