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

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 [xn + y];

Average of n+1 games = [xn + y]/[n+1]

Ans is (A)

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)

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)

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:

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

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

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