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An office has 3 managers and 20 employees.
If admins want to change the office setup to have at least 20% of the work force
(managers and employees) consist of managers,
how many managers need to be hired at a minimum?
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Let x be the number of managers to add.
Then the inequality must be held
>= 0.2.
Multiply both sides by 23+x and simplify
3 + x >= 0.2*(23+x)
3 + x >= 4.6 + 0.2x
x - 0.2x >= 4.6 - 3
0.8x >= 1.6
x >= 1.6/0.8 = 2.
ANSWER. At least, 2 managers should be hired.
Solved.