Plugging In: Invisible Plugging In - Percents

At company _X_, 30% of the employees are below 25 years of age. Of the remaining employees, 60% are 25–50 years old. If 25% of the employees older than 50 years of age are retiring this year, what percent of the total employees are above 50 years of age and are not retiring this year?

Correct. [[snippet]] __Plug In__ 100 for the total number of employees (the invisible variable). Of the total number of employees, 30% of 100 are below 25 years of age (30). Of the 70 that remain, 60% are in the age group 25–50 (42). Of the 28 that remain, 25% are retiring this year, leaving $$28-7=21$$ that are not retiring. The percentage of 21 out of 100 is 21%. (Isn't 100 a magic number with percents?)

Incorrect. [[snippet]]

Incorrect. [[snippet]]

Incorrect. [[snippet]] This is the percentage of all employees over 50 years of age.

Incorrect. [[snippet]]

7%

14%

21%

28%

35%