simplify the following equation
$$ (1-{1\over3})(1-{1\over4})(1-{1\over5})......(1-{1\over n})$$

The following penalty diagram shows the 4 year exam results of the students of 10th standard. Study the diagram and answer the following questions.

State the percentage increase in the first division in the year 2003 as compared to the year 2002:

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

If  $$\sqrt{2}=1.414$$, the value of $${ \sqrt{2}-1\over\sqrt{2}+1}$$  is nearest to 

A number when divided by 5 leaves a remainder 3. What is the remainder when the square of the same number is divided by 5 ? 

Direction: A shopkeeper has some kg. rice of same price. He sold 150 kg. rice at 25 Rs. per kg. and earned a profit of 25%, another 180 kg. rice is sold at a profit of 20% and rest are sold at a loss of 10%. If the shopkeeper earns Rs. 1230 profit on all the rice that he has sold then answers the following question:

If the shopkeeper earns 10% profit instead of 10% loss on the rest rice then find the difference between the old and new profit. 

The volume of a solid right circular cone is 600 π cm³, and the diameter of its base is 30 cm. The total surface area (in cm²) of the cone is:

Kirti decided to spend 45% of her monthly salary on shopping, after spending Rs 11475 she found that this money was 60% of the amount she spent, what is Kirti's salary?