The circumference of a circular park is 264 m. Find the area of the park

One Fermi is equal to 

A trader marks up his goods by 50%. However, he could sell only one-third of his stock at this price. The half of the remaining stock was sold at a discount of 7.14% and the remaining at a discount of 16.67%. Find the overall percentage profit of the trader.

A 20 litre mixture contains milk and water in the respective ratio of 3:2. If 10 litre of the mixture is removed and replaced with pure milk and the operation is repeated once more. At the end of the two removals and replacement, what is the ratio of milk and water in the resultant mixture respectively

36,52,70,90,112,136

1.21,1.44,1.69,1.96,2.25,2.56