The height of a wall is six times its width and the length of the wall is seven times its height. If volume of the wall be 16128 cube m, its width is 

From 2008 to 2009, the sales of a book decreased by 80%. If the sales in 2010 were the same as in 2008, by what percent did it increase from 2009 to 2010?

A man borrows some amount at the rate of 12% per annum at simple interest. After 6 years 8 months, he paid 720 as an interest. Find the amount borrowed by him. 

If a=34, b=c=33, then the value of a3+b3+c3-3abc is 

The number of mainas and parrots in an aviary is in the ratio of (4x + 5) : 4x. If 25 mainas and 10 parrots are added to the aviary, then, the ratio would change to 5: 3. How many mainas are there in the aviary at initial?

If 4x+5y=83 and $$ \ {3x\over2y}={21\over22}$$then what is the value of y-x ?

By Selling 90 pens for Rs. 80 a man loses 20%. What should be the selling price (in Rs.) of 90 pens for 20% profit?

Two poles of equal height are standing opposite to each other on either side of a road, which is 28 metre wide. From a point between them on the road, the angle of elevation  of the top are 30° and 60°. The height of each pole is:-