Median Problem 3

This topic has expert replies
User avatar
Senior | Next Rank: 100 Posts
Posts: 45
Joined: Fri Aug 19, 2016 1:42 am

Median Problem 3

by aditiniyer » Tue Feb 21, 2017 5:36 am
Jim Broke's only source of income comes from his job as a question writer. In this capacity, Jim earns a flat salary of $200 per week plus a fee of $9 for every question that he writes. Every year Jim takes exactly 2 weeks of unpaid vacation. If a regular year consists of 52 weeks and the number of questions that Jim wrote in each of the past 5 years was an odd number greater than 20, which of the following could be Jim's median annual income over the past 5 years ?

A) $22,474
B) $25,673
C) $27,318
D) $28,423
E) $31,227
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Tue Feb 21, 2017 9:26 am
Hi aditiniyer,

This question can be solved by TESTing THE ANSWERS.

Here, we're given Jim"s pay rate ($200/week + $9 per question), we're told that he works for 50 weeks out of the year and that he writes an ODD number of questions greater than 20. As an example, I'm going to calculate the LEAST amount of money that he could have earned....

IF... he wrote just 21 questions for the year, he would have made...

$200(50) + $9(21) = 10,000 + 189 = $10,189

Now we have the 'framework' to figure out what his MEDIAN income COULD have been: $10,000 + $9(ODD number). We can use the 'rule of 9' to eliminate answers that aren't possible:

Answer A: $22,474 - $10,000 = $12,474 IS divisible by 9, BUT is it an ODD multiple of 9.... 12474/9 = 1386 NOT ODD. Eliminate A
Answer B: $25,673 - $10,000 = $15,673 NOT divisible by 9. Eliminate B
Answer C: $27,318 - $10,000 = $17,318 NOT divisible by 9. Eliminate C
Answer D: $28,423 - $10,000 = $18,423 IS divisible by 9, BUT is it an ODD multiple of 9.... 18423/9 = 2047 IT'S ODD.

Since we can easily add or subtract $18 increments to this total, this COULD be the median value for the 5-year period.

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Tue Feb 21, 2017 9:18 pm
aditiniyer wrote:Jim Broke's only source of income comes from his job as a question writer. In this capacity, Jim earns a flat salary of $200 per week plus a fee of $9 for every question that he writes. Every year Jim takes exactly 2 weeks of unpaid vacation. If a regular year consists of 52 weeks and the number of questions that Jim wrote in each of the past 5 years was an odd number greater than 20, which of the following could be Jim's median annual income over the past 5 years ?

A) $22,474
B) $25,673
C) $27,318
D) $28,423
E) $31,227
Hi aditiniyer,

We have Jim's remuneration = $(500 x 200 + 9 x # of qns)

Remuneration = 10000 + 9 x (an odd number) = Even + Odd = Odd.

This means that Jim's yearly remuneration would be an odd number for each of the 5 years, thus the median would also be an odd number. This way, we can discard option A and C.

Let's test the other three options B, D, and E.

Option B: $25,673

The remuneration through question making = $25,673 - 10000 = 15,673.

Since 15,673 = 9 x (an odd number), 15,673 must be divisible by '9.'

We know the divisibility rule of '9': Sum of the digits of a number must be divisible by 9.

Sum of digits of 15,673 = 1+5+6+7+3 = 22. Since 22 is not divisible by 9, option B cannot be a median value.

Option D: $28,423

The remuneration through question making = $28,423 - 10000 = 18,423.

Since 15,673 = 9 x (an odd number), 15,673 must be divisible by '9.'

We know the divisibility rule of '9': Sum of the digits of a number must be divisible by 9.

Sum of digits of 18,423 = 1+8+4+2+3 = 18. Since 18 is divisible by 9, and 18,423/9 = 2047 (an odd number), option D can be a median value.

Since this is a could be type of question, we need not test option E.

The correct answer: D

Hope this helps!

Relevant book: Manhattan Review GMAT Math Essentials Guide

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Beijing | Auckland | Milan | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

GMAT Instructor
Posts: 2630
Joined: Wed Sep 12, 2012 3:32 pm
Location: East Bay all the way
Thanked: 625 times
Followed by:119 members
GMAT Score:780

by Matt@VeritasPrep » Fri Mar 03, 2017 4:26 am
I can't believe I didn't write this question, it's exactly the sort of humor I used to sneak into the problems I wrote for a SAT testing company back when that ... was my only source of income. (Matt Broke, we hardly knew ye.)

Just out of curiosity, where IS this from? Wondering who my kindred spirit might be.