For the following questions answer them individually
$$\frac{4}{7}  of  \frac{8}{9} \div \frac{8}{7} \times 180  of  \frac{1}{9} = ?$$
If cost prices of 100 note books is same as selling price of 80 note books. What is the percent gain ?
A person bought an item and sold it at a loss of 5%. If he had bought it for 10% less and sold it for ₹ 170 more, he would have had a profit of 20%, Find the cost price of this item. (nearest to ₹1)
A pipe can fill a cistern in 20 minutes where as the cistern when full can be emptied by a leak in 28 minutes. When both are opened, The time taken to fill the cistern is:
A certain sum amounts to ₹ 756 in 2 years and to ₹ 873 is $$3\frac{1}{2}$$ years at a certain rate of simple interest. The rate of interest per annum is:
A square with maximum possible side is drawn in a circle of radius 12 cm. What is the area of square?
What value should come in place of the question mark (?) in the following questions?
$$31 \div 3 \times 15 = ?$$