GMATPrep PS Question with Table

[mpaudena]

Okay, there is a table and the info is as such:

Amount earned per day: $96 -- $84 -- $80 -- $70 -- $48
Number of days: 4 -- 7 -- 4 -- 3 -- 2

A student worked for 20 days. For each of the amounts shown in the first row of the table, the second row gives the number of days that the student earned that amount. What is the median amount of money that the student earned per day for the 20 days?

A) 96

B) 84

C) 80

D) 70

E) 48

Thanks in advance.

[hitmewithgmat]

It takes less than ten seconds to solve this problem only if you know the concept of "median". So don't worry about it when you come across this type of question afterwards.

What is the median of 20days? Yes, 10 days.
So, find the 10 days that falls on the range.
That is second one, 7(because 4 plus 7 is 11 and 10 is right here!) So, the answer is $84. B.

[mpaudena]

It takes less than ten seconds to solve this problem only if you know the concept of "median". So don't worry about it when you come across this type of question afterwards.

What is the median of 20days? Yes, 10 days.
So, find the 10 days that falls on the range.
That is second one, 7(because 4 plus 7 is 11 and 10 is right here!) So, the answer is $84. B.

Okay but why are we starting in that sequence? I figured that I would start from the number of days with the lowest number and then go up. Then when I got to the 10th day I would pick the amount of money that it fell on.

I.e., 2 days - $48 plus 3 days for $70 plus 4 days for $80 that is a total of 9 days. The next lowest number of days is 4 days for $96 so the 10th day will have an amount of $96 is we start the sequence using smallest to largest number of days. It seems that you assumed that we should just use the numbers as they appear from left to right on the screen. I don't see why the test makers should think that we all will make that assumption.

[ssuarezo]

It takes less than ten seconds to solve this problem only if you know the concept of "median". So don't worry about it when you come across this type of question afterwards.

What is the median of 20days? Yes, 10 days.
So, find the 10 days that falls on the range.
That is second one, 7(because 4 plus 7 is 11 and 10 is right here!) So, the answer is $84. B.

Okay but why are we starting in that sequence? I figured that I would start from the number of days with the lowest number and then go up. Then when I got to the 10th day I would pick the amount of money that it fell on.

I.e., 2 days - $48 plus 3 days for $70 plus 4 days for $80 that is a total of 9 days. The next lowest number of days is 4 days for $96 so the 10th day will have an amount of $96 is we start the sequence using smallest to largest number of days. It seems that you assumed that we should just use the numbers as they appear from left to right on the screen. I don't see why the test makers should think that we all will make that assumption.

Hi:
First, the median of 20 is 10.5, am I wrong? there's no unique median value, so, we take an average of 10 and 11. Second, I need 10.5 days, as they come in time, not in an specific order. The table shows it that way, at least, that's what I assumed and that's the way I understand it.
Silvia

[vivek.kapoor83]

Ans should be 84
as no seq is mentioned
so u have start as table is given. i.e 96 $ for 4 days and then 84$ fo 7 days and blah -2
now the median of 20 terms would be avg of 10 & 11 term,
as in 10 th day - 84 $
11 th day - 84 $

taking avg comes out to be 84 $
so ans is 84 $(took me less than 10 sec as said above)

[mpaudena]

Ans should be 84
as no seq is mentioned
so u have start as table is given. i.e 96 $ for 4 days and then 84$ fo 7 days and blah -2
now the median of 20 terms would be avg of 10 & 11 term,
as in 10 th day - 84 $
11 th day - 84 $

taking avg comes out to be 84 $
so ans is 84 $(took me less than 10 sec as said above)