Question 217 Problem Solving 2018 GMAT Official Guide

Question 217 Problem Solving 2018 GMAT Official Guide

Video explanation: For the past n days, the average (arithmetic mean) daily…

Comments

Alejandrosays

I’ve got a question.

If in the numerator we use (n-1) and in the numerator we use “n”, the answer I get is 8 instead of 7, which intuitively doesn’t make a lot of sense to me. Am I missing something? using that nomenclature I’d then need to deduct one to get to that point in time they as asking for, right?

Here $n$ is defined as the number of days for which the average daily production was $50$ units per day. You could define your own variable, say $m$, which represents the total number of days including the additional day with the production of $90$ units. In that case, $m$ will turn out to be $8$, and as you said in your response the value of $n$ would then be $1$ less than that, which is equal to $7$.

Alejandro says

I’ve got a question.

If in the numerator we use (n-1) and in the numerator we use “n”, the answer I get is 8 instead of 7, which intuitively doesn’t make a lot of sense to me. Am I missing something? using that nomenclature I’d then need to deduct one to get to that point in time they as asking for, right?

many thanks

GMAT Quantum says

Here $n$ is defined as the number of days for which the average daily production was $50$ units per day. You could define your own variable, say $m$, which represents the total number of days including the additional day with the production of $90$ units. In that case, $m$ will turn out to be $8$, and as you said in your response the value of $n$ would then be $1$ less than that, which is equal to $7$.