Problem Solving

hi there,

Could you explain to me what is the concept ? step by step :


Of the 800 employees of Company X, 70 percent have been with the company for at least ten years. If y of these “long-term” members were to retire and no other employee changes were to occur, what value of y would reduce the percent of the “long-term” employees in the company to 60 percent?

a) 200
b)160
c)112
d)80
e)56


answer A

it looks confusing, but if u break up into small stmts u see it's simple.

70% of 800 is 560. so 240 are not long term.
(560-y)/(800-y)=0.6
this is equal to 560-y=480-0.6y, solve for y and u get 200

if you can't really see all of this, plug in the answer choices, get any of them, subtract to 560 and see if it yields 60%...

hope it helps...