A shopkeeper buys 100 mangoes at Tk. 12 each. He sells 60 mangoes at Tk. 17.40 each and r mangoes at Tk. 11.31 each. The shopkeeper makes a profit of at least 10%. Find the least possible value of x.

Lamia owns a hairdressing salon. She borrows Tk. 2,500 from a bank to make improvements to her beauty salon. She is charged 4.5% per year compound interest. She pays the money back after 3 years. Calculate the total amount Lamia must pay to the bank.

To make a pizza, the following round baking tray is completely filled with dough to a depth of d mm. The open cylinder holds 500cm of dough. Calculate the depth of the dough d mm, giving your answer correct to the nearest millimeter.