Percent and Two variable model

Percent and Two Variable Model:

1. The price of the loaf of bread was increased by 20%. How many loaves can be purchased for the amount of money that used to buy 300 loaves?

(A) 240           (B) 250       (C) 280        (D) 320           (E) 360

2. A company decreased the price of its main product by 50%. Subsequently, the number of units sold increased such that the total revenue remained unchanged. What was the ratio of the percent increase in the units sold to the percent decrease of the original price for this product? 
(A)  0.5      (B)  1.0      (C)  1.5       (D)  2.0      (E)  4.0

3. The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
(A)  100% decrease   (B)  50% decrease   (C)  40% decrease  (D)  40% increase     

(E)  50% increase

4.  A part time employee whose hourly wages was increased by 25 percent decided to reduce the number of hours worked per week. So that the employee's total weekly income would remain unchanged. By what percent should the number of hours worked be reduced?

(A) 12.5 %        (B) 20%           (C) 25 %       (D) 50 %          (E) 75 %

5. If kens salary were 20%less than Lorena’s. If Lorena's salary is $60, 000, what is kens salary?

(A)  $36,000       (B) $40,000     (C) $42,500         (D) $42,850        (E)  $45,000

6. After one year at her job, Sharon received a 50% increase on her $1,000 weekly salary , bob , who originally made $

7. Before Maria changed jobs, her salary was 24 percent more then Julio's salary, after Maria changed jobs, her new salary was 24 percent less than her old salary.

Column A: Julio’s salary                                         Column B: Maria’s new salary