The population of Houston was 1,900,000 in 2000. It grew to 2,100,000 in 2010. Find the percent of increase.
a. 10.5%
b. 20%
C. 21%
d. 40%

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)