If a basketball team scores an average (arithmetic mean) of x points

Question

The Official Guide For GMAT® Quantitative Review, 2ND Edition

If a basketball team scores an average (arithmetic mean) of x points per game for n games and then scores y points in its next game, what is the team's average score for the n+1 games?

(A)  \frac{(nx + y)}{(n + 1)}

(B)  x + \frac{y}{(n + 1)}

(C)  x + \frac{y}{n}

(D)  \frac{n(x + y)}{(n + 1)}

(E)  \frac{(x + ny)}{(n + 1)}

Problem Solving  
 Question:  116
 Category:   Arithmetic  Statistics
 Page:  76
 Difficulty:  550

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Bunuel · Accepted Answer

SOLUTION

If a basketball team scores an average (arithmetic mean) of x points per game for n games and then scores y points in its next game, what is the team's average score for the n+1 games?

(A)  \frac{(nx + y)}{(n + 1)}

(B)  x + \frac{y}{(n + 1)}

(C)  x + \frac{y}{n}

(D)  \frac{n(x + y)}{(n + 1)}

(E)  \frac{(x + ny)}{(n + 1)}

Total points for n games = (number of games)*(average number of points) = nx;

Total points for n + 1 games = nx + y;

The average number of points for n +1 games =  \frac{(total \ points \ for \ n + 1 \ games)}{(number \ of \ games)}= \frac{(nx + y)}{(n + 1)} .

Answer: A.

murilomoraes · Answer

For me is A If you considered X points to n games so you mean will be (X*N)/N and you play another game and score Y points, going in that way will be X*N+Y/N+1 so A it is

nutshell · Answer

The sum of points for the first n games will be (Average points for n games * no. of games(n)): xn
So, if y points have been added, the total no. of points in (n+1) games will be  ;

Average of n+1 games =  /

Ans is (A)

mbaapp1234 · Answer

Average = total/number

x = total/number

Instead of creating a variable t for total, you should use xn.

Then the new score is y, so the new total is xn (prior total) + y (increment)

The new total number is n+1.

(xn+y)/(n+1)

CyberStein · Answer

After reading the question, analyze the givens.

Let X = points average current games
Let N = number of current games
Y = points of next game
N + 1 = Number of current games plus the next game

Sum points / Total Games = Average
Average x Total Games = Sum points
Average of current games x total current games + points of next game / total number of games including next game

Therefore,

(X x N) + Y / N + 1

(A)

EMPOWERgmatRichC · Answer

Hi All,

This question can also be solved by TESTing VALUES.

We're told that a team scored an average of X points per game for the first N games, then scores Y points in the next game....

IF.... 
X = 2 
N = 3 
Y = 4

We have a total of (2)(3) + (4)(1) = 10 points scored over 4 games.

We're asked for the AVERAGE SCORE for all games. In this case, the average is 10/4 = 2.5

Although the original question does not include it, I assume that each numerator and each denominator is meant to have PARENTHESES around it...

Answer A: 10/4 = 2.5 This is a MATCH 
Answer B: 6/4 = 1.5 NOT a match 
Answer C: 6/3 = 2 NOT a match 
Answer D: 18/4 = 4.5 NOT a match 
Answer E: 14/4 = 3.5 NOT a match

Final Answer:  A

GMAT assassins aren't born, they're made, 
Rich

ScottTargetTestPrep · Answer

The sum of points for n games is nx. If the team scores y points in the next game the new average is:

(nx + y)/(n + 1)

Answer: A

totaltestprepNick · Answer

A https://www.youtube.com/watch?v=fDT0t1g98HM Nick Slavkovich, GMAT/GRE tutor with 20+ years of experience tutoring@totaltestprep.net

If a basketball team scores an average (arithmetic mean) of x points

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