Overlapping Sets-800 Employees, 10yrs Exp.

Question

Of the 800 employees in a certain company, 70% have serviced more than 10 years. A number of y of those who have serviced more than 10 years will retire and no fresh employees join in. What is y if the 10 years employees become 60% of the total employees?

Hi , Could someone give answer for the above with explanation.
Also I have attached an explanation for the same using matrix method. Is that correct approach?

Any other simpler way of reasoning this question?

Bunuel · Answer

Step by step:

0.7*800=560  employees have serviced more than 10 years;

We are told that after  y   of those employees  leave the company the # of employees who have serviced more than 10 years ( 560-y ) become 60% of a new total, which will be  800-y , so:  0.6*(800-y)=(560-y)  -->  y=200 .

helloanupam · Answer

Thanks for the crisp answer. I did not discern the sentence the way you did. It made it very easy.

fluke · Answer

(800 * 70/100) - y = (60/100) * (800 - y)
560 - y = (3/5)*(800-y)
2800 - 5y = 2400 - 3y
400 = 2y
200 = y.

I didn't see this question as an overlapping set question.

Overlapping Sets-800 Employees, > 10yrs Exp.

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