Andy earns $200 per week working part-time at a fast food restaurant. Last week he was ill, so he only earned $120. By what percent did Andy's salary decrease

Andy's Salary decreases by 40% in the week he was ill.

Step-by-step explanation:

Step 1; To find the percent by which Andy's salary decreases we must find the difference between the maximum salary and the obtained salary. The maximum salary is the amount of money he would have gotten if he went all days. The maximum salary is $200 a week. The salary that Andy got for working the previous week was $120.

Difference in salaries = Maximum salary - Obtained Salary = $200 - $120 = $80

Step 2; To find the percent decrease in salary in terms of maximum salary, we divide the difference in salaries by the maximum salary. We multiply this value by 100 to get it in terms of percentage.

Percent decrease in Andy's salary = Difference in salaries/Maximum salary*100

= $80/$200 * 100 = 0.40 * 100 = 40%

So Andy's salary decreases by 40% in the week he was ill.