Explain why monopolies do exist?

Good guys i hope you will me about this question,, plase

Consumer surplus is: the difference between the price of a product and what consumers were willing to pay for the product. the difference between the discounted price of a product and its retail price. the difference between the price paid by consumers and the price required of producers. the difference between the price of a product and consumers' valuation of the last unit of the product purchased.

In canada, the reference base period for the cpi is 2002. by 2012, prices had risen by 21.6 percent since the base period. the inflation rate in canada in 2013 was 1.1 percent. calculate the cpi in canada in 2013. hint: use the information that “prices had risen by 21.6 percent since the base period” to find the cpi in 2012. use the inflation rate formula (inflation is the growth rate of the cpi) to find cpi in 2013, knowing the cpi in 2012 and the inflation rate. the cpi in canada in 2013 is round up your answer to the first decimal. 122.9 130.7 119.6 110.5