A trader allows a trade discount of 20% and a cash discount of $$6{1\over4}\%$$ on the marked price of the goods and gets a net gain of 20% of the cost. By how much above the cost should the goods be marked for the sale? 

Each side of a square is 12 cm long. The perimeter of this square is equal to the perimeter of a rectangle whose length is 16 cm. What will be the area of this rectangle?

Directions : Study the following pie chart carefully and answer the questions. The pie chart represents the percentage of people involved in various occupations.
Total number of people = 20000

The difference between the maximum number of people involved and minimum number of people involved in various professions is 

A prism with a right triangular base is 25 cm high. If the shorter sides of the triangle are in the ratio of 1 : 2 and the volume of the prism is 100 cm³ , what is the length of the longest side of the triangle?

$$4a-{4\over a}+3=0$$ then the value of :   $$ a^3-{1\over a^3}+3=?$$

if $$ sinA= {4\over 5}$$, then what is the value of $$sin^2A$$

What should come in place of the question mark '?' in the following number series?

7, 13, ?, 49, 97, 193

If x = 2 then the value of x³ + 27x² + 243x + 631 is