A single discount equivalent to two successive discounts of $$ {12{1\over 2}}{\%}$$ and 20% is

 A retailer purchase 40 pens at the cost price of 36 pens from a wholeseller . If he sells all of them at a discount of 1 %, then what is his profit percent? 

$$ {\sqrt{8\ {^{3}\sqrt{729}}}=?}$$

Study the graph carefully and answer the following questions.

What is the average production of the five states in the year 1994-95 taken together?

Two men start walking together to a certain destination, one at 6 km/hr and other at 7.5 km/hr. The later arrives an hour before the former. The distance is ?

The covered surface area of  a cone of radius 8 cm and height 6 cm is double the covered surface area of a cylinder of radius 4 cm. Find the height of the cylinder?

Which of the following simplification value of $$ {(secA-cosA)^{2}}+{(cosecA-sinA)^{2}}-{(cotA-tanA)^{2}}$$ ?

If (x + k ) is the common factor of x² + ax + b and x² + cx + d , then what is k equal to ?