Pls help, chart prob.

[tracyyahoo]

Age Category (in years) Number of Employees
Less than 20......................29
20 - 29 ..........................58
30 - 39 ..........................36
40 - 49 ..........................21
50 - 59 ..........................10
60 - 69 ...........................5
70 and over........................2

There are 161 employees at Company X. The above table shows the age category of all the employees. According to the table, if m is the median age, in years, of the employees at Company X, then m must satisfy which of the following?

A. 20 ≤ m ≤ 29
B. 25 ≤ m ≤ 34
C. 30 ≤ m ≤ 39
D. 35 ≤ m ≤ 44
E. 40 ≤ m ≤ 49
Answer: A

hOW do I approach this

[GmatMathPro]

If you list the ages of the employees from lowest to highest, the median age would be the 81st one because there are 161 total employeed. There are 80 from 1-80 and 80 from 82-161, so 81 must be the middle. The chart tells us that 29 employees have an age less than 20, and 58 employees have an age between 20-29. 29+58=87, so the 81st employee must be in that 20-29 range.

[phoenix111]

I guess median like middle value if things are sorted. ( I dont actually remember )

If that is true, the answer would be A.

Total Employees : = 161
So if they are sorted by age, then median : 81st employee's age

The chart given actually provides us the sorted data:
So we need to find in which range 81st employee falls.

<20 : 29 ( Total : 29)
20-29 : 58 ( Total 87 ) 81st lies here. Ans: 20-29