Take a look at this, problem or not

Question

Take a look at this, problem or not?

anandsebastin · Answer

D)43% 

When overall average = 90, 

70 +2x/3 = 90
Simplifying, 
x=100 = average score needed on the remaining 2/3rds of evaluations.

She needs an increase of (100-70)*100/70 = 42.8 = 43%

Rayn · Answer

Tell me, is the fact that the total score is over 110 irrelevant?

anandsebastin · Answer

In this case, I'd say it is irrelevant.

Rayn · Answer

For the exam sake, how would you discern whether to consider it or not?
Well, why did you ignore it?

SimaQ · Answer

I ignored that data because i indicate on the paper what i need to know....

Average=S/x

include what we need to achieve:

(70+(2/3)x)/2=90
70+(2/3*x)=180
2/3x=110
x=330/2
x=165

We know the score from the firs 1/3 of the supervisors.....

70=S/(1/3)x
70*(1/3)x=S... replace x with 165
70*55=S
S=3850... we know the sum of evaluations from 1/3 of the supervisors

We need to achieve:
90x=S
S=14850

So from the 2/3 of supervisors we need to achieve a total score of:
14850-3850=11000
or we need to achieve the average score from 2/3 of supervisors....
A=11000/(2/3)*165
A=11000/110
A=100

Darlene must increase her current average of 70 to 100:
30/70=0.43=43%

cicerone · Answer

Let's keep it simple...........

Let's suppose that there are only 3 evaluations.
He needs an average of 90. So total has to be 270

In one evaluation he got 70
So remaining two evaluations he should get 200
So the average of remaining two evaluations must be 100.

So it increased by 30/70 = 42.84% 

So 43%

yezz · Answer

Same work like Cicerone's

SimaQ · Answer

yep this apprach is the best...

My approach was just to see why we do not need the 110 figure mentioned in the question....

asaf · Answer

(70 + 2X)/3 = 90
2X = 270 - 70 ; X = 100

% Increase (100 - 70)/70 * 100
= 300/7
= 42.7
approximately 43%

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