BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

simple question (starts at 600 level)

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 1337
Joined: Sat Dec 27, 2008 6:29 pm
Thanked: 127 times
Followed by:10 members

simple question (starts at 600 level)

by Night reader » Sun Oct 31, 2010 4:50 pm
A student has obtained the scores 89 and 95 on his two midterm exams for a certain class. The student's final exam score receives 2.5 the weight of each of his two midterm exam scores; the course grade is based on the midterm and final exam scores only. What must be the student's score on the final exam for his course grade 92?

(A) 95
(B) 94
(C) 92
(D) 93
(E) 97
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com
Top
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 307
Joined: Sun Jul 11, 2010 7:52 pm
Thanked: 36 times
Followed by:1 members
GMAT Score:640

by limestone » Sun Oct 31, 2010 6:52 pm
Hi,

The average score for his midterm exams is : (95+89) /2 = 92
His course grade is 92,
thus, regardless of the weight of the final test,
the final test must have a score of 92 to keep the average unchanged.

Pick C.
"There is nothing either good or bad - but thinking makes it so" - Shakespeare.
Top
Legendary Member
Posts: 1337
Joined: Sat Dec 27, 2008 6:29 pm
Thanked: 127 times
Followed by:10 members

by Night reader » Sun Oct 31, 2010 7:28 pm
limestone wrote:Hi,

The average score for his midterm exams is : (95+89) /2 = 92
His course grade is 92,
thus, regardless of the weight of the final test,
the final test must have a score of 92 to keep the average unchanged.

Pick C.
Like your short-cut. Below I post algebraic solution for such kind of problems (in case, average on midterms would not be equal to the course grade)

(89+95+2.5*F) / 4.5 (or 2 midterms and 2.5 weight) = 92
184+2.5F = 92*4.5
92*4.5- 184 = 2.5F, F=92

Now try different weight e.g. 2 (not in problem)
(89+95+2F)/4 = 92
184+2F = 92*4, F=92

The problem essentially tested knowledge of weighted averages.
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com
Top
Legendary Member
Posts: 1119
Joined: Fri May 07, 2010 8:50 am
Thanked: 29 times
Followed by:3 members

by diebeatsthegmat » Sun Oct 31, 2010 11:57 pm
Night reader wrote:
limestone wrote:Hi,

The average score for his midterm exams is : (95+89) /2 = 92
His course grade is 92,
thus, regardless of the weight of the final test,
the final test must have a score of 92 to keep the average unchanged.

Pick C.
Like your short-cut. Below I post algebraic solution for such kind of problems (in case, average on midterms would not be equal to the course grade)

(89+95+2.5*F) / 4.5 (or 2 midterms and 2.5 weight) = 92
184+2.5F = 92*4.5
92*4.5- 184 = 2.5F, F=92

Now try different weight e.g. 2 (not in problem)
(89+95+2F)/4 = 92
184+2F = 92*4, F=92

The problem essentially tested knowledge of weighted averages.
can you explain more about the knowlegde of weighted average?
Top
Post new topic Post Reply
• Page 1 of 1