Lola is a software saleswoman. her base salary is $1900, and she makes about $40 for every copy of hostory is fun she sells.

let p represent her total pay (in dollars), and let n represent the number of copies of history is fun she sells. write an equation relating p to n. then use this equation to find her total pay if she sells 24 copies of history is fun.

Since her base salary is $1900, the money she makes by selling copies of History is Fun gets multiplied by $40 and that gets added to her base salary. 
So the equation would be = P+40N
Since she sells 24 copies, her total pay would be = 1900+(40*24) 
                                                                                    = 1900 + 960
                                                                                    = $2860 

Solve for the difference between the price of the stocks at the beginning of the day and at the end. 

                                     d = $4.05 - $3.72 = $0.33

Divide this value by the original value of the stocks and multiply by 100% to get the rate of change.

                      ($0.33 / $3.72) x 100% = 8.87%

Thus, the answer is letter A. 8.9%.