Weighted Average problems - Need insight on this topic

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Bonnie scores 75 on a midterm that is worth 40% of her grade, and she scores 90 on the final that is worth 60% of her grade. What is Bonnie's weighted grade after both exams?

54
84
168.75
187.5
45

Eventhough it may be a simple weighted average problem for many, i am posting this for getting insight into the this topic problems in GMAT. I had a difficulty in understanding the answer??
Experts can you throw light on this topic?
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by KapTeacherEli » Mon Jun 25, 2012 8:03 pm
Hi Karthik,

Weighted Average problems follow the same basic formula every time:

(Average 1)(Percentage 1) + (Average 2)(Percentage 2)... + ... (Average n)(Percentage n) = Overall Average.

So, in this case:

75 * 40% + 90 * 60% = 84, choice B.

If these are giving you trouble, you can read a litte more about them in this blog post about Mixtures. The Weighted Average formula is a special case of solving mixtures, so it should help.

Good luck!
Eli Meyer
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Cambridge, MA
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by Anurag@Gurome » Mon Jun 25, 2012 9:09 pm
karthikpandian19 wrote:Bonnie scores 75 on a midterm that is worth 40% of her grade, and she scores 90 on the final that is worth 60% of her grade. What is Bonnie's weighted grade after both exams?
Just note that whatever is Bonnie's weighted score is after both the exams, it will be between 75 and 90.

Only option that satisfy this condition is 84.

The correct answer is B.
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by karthikpandian19 » Mon Jun 25, 2012 9:36 pm
Hi Eli,

Th blog page is not found at the link that you had provided. Can you provide me the right link?
KapTeacherEli wrote:Hi Karthik,

Weighted Average problems follow the same basic formula every time:

(Average 1)(Percentage 1) + (Average 2)(Percentage 2)... + ... (Average n)(Percentage n) = Overall Average.

So, in this case:

75 * 40% + 90 * 60% = 84, choice B.

If these are giving you trouble, you can read a litte more about them in this blog post about Mixtures. The Weighted Average formula is a special case of solving mixtures, so it should help.

Good luck!
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON

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by karthikpandian19 » Mon Jun 25, 2012 9:38 pm
Anurag,

Is there any reference material with you wrt the GMAT for Weighted average?
Anurag@Gurome wrote:
karthikpandian19 wrote:Bonnie scores 75 on a midterm that is worth 40% of her grade, and she scores 90 on the final that is worth 60% of her grade. What is Bonnie's weighted grade after both exams?
Just note that whatever is Bonnie's weighted score is after both the exams, it will be between 75 and 90.

Only option that satisfy this condition is 84.

The correct answer is B.
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON

---If you find my post useful, click "Thank" :) :)---
---Never stop until cracking GMAT---

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by shekhar.kataria » Wed Jun 27, 2012 1:01 am
Bonnie scores 75 on a midterm that is worth 40% of her grade, and she scores 90 on the final that is worth 60% of her grade. What is Bonnie's weighted grade after both exams?
I am confused in the language of the problem "40 % of her grade"

It seems to suggest that that the marks scored i.e 75 is 40% of overall which takes the full 100 percent to 187.5. Similarly 150 is the overall score in which he scores 90 marks.

But cannot come to the right conclusion after this. Help Please..
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by karthikpandian19 » Wed Jun 27, 2012 3:52 am
Even i am looking for some experts to explain.

Can any expert clarify the the question / confusion ?
shekhar.kataria wrote:
Bonnie scores 75 on a midterm that is worth 40% of her grade, and she scores 90 on the final that is worth 60% of her grade. What is Bonnie's weighted grade after both exams?
I am confused in the language of the problem "40 % of her grade"

It seems to suggest that that the marks scored i.e 75 is 40% of overall which takes the full 100 percent to 187.5. Similarly 150 is the overall score in which he scores 90 marks.

But cannot come to the right conclusion after this. Help Please..
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON

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by KapTeacherEli » Wed Jun 27, 2012 6:54 am
Hi folks,

Here is the proper link to the blog:

https://blog.kaplangmat.com/2010/12/22/g ... -problems/

As for the other question, grades are always out of 100% unless otherwise specified. So, 40% of that final grade is the midterm. However, the midterm is also graded on a 100 point scale, which means that she got 75/100 = 75% credit. As a result, her score on her essay contributed 75% of 40% of her final grade, or .75*40 = 30 points. Similar logic tells you how many points were added to her final grade by her final.

I hope this clears things up!
Eli Meyer
Kaplan GMAT Teacher
Cambridge, MA
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by karthikpandian19 » Wed Jun 27, 2012 2:22 pm
Hello Eli,

Still the link is not opening. This time i have attached the image. Please check
KapTeacherEli wrote:Hi folks,

Here is the proper link to the blog:

https://blog.kaplangmat.com/2010/12/22/g ... -problems/

As for the other question, grades are always out of 100% unless otherwise specified. So, 40% of that final grade is the midterm. However, the midterm is also graded on a 100 point scale, which means that she got 75/100 = 75% credit. As a result, her score on her essay contributed 75% of 40% of her final grade, or .75*40 = 30 points. Similar logic tells you how many points were added to her final grade by her final.

I hope this clears things up!
Image
Regards,
Karthik
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by KapTeacherEli » Wed Jun 27, 2012 3:46 pm
The link is correct; the problem is with BeatTheGMAT! Try copy-pasting into your browser bar!
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by karthikpandian19 » Wed Jun 27, 2012 4:33 pm
Yeah,....it works....thank you
KapTeacherEli wrote:The link is correct; the problem is with BeatTheGMAT! Try copy-pasting into your browser bar!
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON

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---Never stop until cracking GMAT---