There are four numbers in a set. The mean of the three smallest numbers is 9, whereas the mean of the three largest ones is 11. What is the range of the data set? 

Direction : What should come in place of the question (?) in the following question.

35% of 430 + ? % of 360 = 276.5

What approximate value will come in place of the question mark (?) in the following questions?

175 x 28 + 275 x 27.98 =? 

If the 5 digit number 538xy is divisible by 3, 7 and 11, then the value of (x² +y²)  is:

1332.89+171.928+17.01 +?²=1690.87

In an office, there are 108 tables and 132 chairs. If $${1\over6} $$ of the tables and $${1\over4} $$ of the chairs are broken. How many people can work in the office if each person requires one table and one chair? 

A number whose one - fifth part increased by 4 is equal to its one - fourth part diminished by 10 is: 

Unit digit in (264)¹⁰²+(264)¹⁰³ is: