Anu was earning $75000 in 2010 and was able to afford the same standard of living as her mother when she was of Anu's age in 1980 and was earning $25,000. The level of prices as indicated by CPI was 75 in 1980. Can you calculate by how much have prices increased from 1980 to 2010?

1)Not enough information provided

2)Prices have increased by two times from 1980 to 2010

3)Prices have increased by three times from 1980 to 2010

4)Prices have increased by 225%