What approximate value should come in the place of question mark (?) in the following question?
 (8423 + 3120 + 6543) ÷ (1536 + 377 + 189) = ?

The bar graph given below shows the sales of books (in thousand number) from six branches - B1, B2, B3, B4 , B5 and B6 of a publishing company during two consecutive years 2000 and 2001.

Find the percentage (approximate) of the average sales of branches B2, B4 and B6 in the year 2001 to the average sales of branches B1, B3 and B5 in the year 2001.

If $$ {x=2-2^{1\over 3}+2 ^{2\over 3}}$$, then the value of $$ {x^{3}-6x^{2}+18x+18}$$.

The perimeter of a square and an equilateral triangle is the same if the length of the diagonal of the square is $$ {12 \ sqrt {2}} $$ cm. If, what will be the area of the triangle?

What is the sum of all natural numbers between 100 and 400 which are divisible by 13? 

For what value of m will the system of equations 17x+my+102=0 and 23x+299y+138=0 have infinite number of solutions? 

A and B under took a work Rs 2200. A alone can do the work in 10 days and B alone can do the work in 12 days. If they work together, then what will be the difference (in Rs) in the amount they receive?  

Gold is 19 times as heavy as water and copper is 9 times as heavy as water. In what ratio should these metals be mixed so that the mixture may be 15 times as heavy as water?