Find the square root of  $$ {k+l+m+n+2\sqrt{ml+mk}+2\sqrt{mn}+2\sqrt{kn+ln}}$$

If $$ {\sqrt{1+{473\over{256}}}=1+{x\over 16}}$$ then what does x equal to ?

Tank is normally filled in 8 hours but takes 2 hours longer to fill because of a leak in its bottom. If the cistern is full, in how many hours will the leak empty it? 

The difference between the average of squares of the last four numbers and the product of the first two numbers of 6 consecutive odd numbers is 114. Find the first number.

If * means adding 6 times the second number to the first number then ( 1 * 2 ) *   3 equals : 

The compound interest on Rs. 6250 at 12% per annum for 1 year, compounded half-yearly is

In a factory, 60 workers can stitch 120 m of clothes in 7 days, what length of clothes can be stiched by 70 workers in 5 days?

The volume of the largest right circular cone that can be cut out of a cube of edge 14 cm.