a) A firms annual sales rise from 50 000 to 55 000 from one year to the next. Express the rise as a percentage of the original.

b) Investments fall during the course of a year by 7%. Find the value of an investment at the end of the year if it was worth e9500 at the beginning of the year.

c) The government imposes a 15% tax on the price of a good. How much does the consumer pay for a good priced by a firm at e1360?