GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Oct 2019, 16:25

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

## Events & Promotions

### Show Tags

26 Aug 2018, 21:24
1
1
00:00

Difficulty:

35% (medium)

Question Stats:

71% (02:01) correct 29% (02:26) wrong based on 82 sessions

### HideShow timer Statistics

Every week, Renee is paid $40 per hour for the first 40 hours she works, and$80 per hour for each hour she works after the first 40 hours. How many hours would Renee have to work in one week to earn an average (arithmetic mean) of $60 per hour that week? (A) 60 (B) 65 (C) 70 (D) 75 (E) 80 _________________ VP Status: Learning stage Joined: 01 Oct 2017 Posts: 1011 WE: Supply Chain Management (Energy and Utilities) Re: Every week, Renee is paid$40 per hour for the first 40 hours she work  [#permalink]

### Show Tags

26 Aug 2018, 21:39
2
2
Bunuel wrote:
Every week, Renee is paid $40 per hour for the first 40 hours she works, and$80 per hour for each hour she works after the first 40 hours. How many hours would Renee have to work in one week to earn an average (arithmetic mean) of $60 per hour that week? (A) 60 (B) 65 (C) 70 (D) 75 (E) 80 Renee makes$40*40 hours=$1600 in first 40 hours Let 't' be the no of hours Renee would work. Given, Renee makes$80 per hour for each hour she works after the first 40 hours. So, she makes an additional pay $80*(t-40)hours for every hour after 40 hours. So, $$\frac{1600+80(t-40)}{t}=60$$ Or, 1600+80t-3200=60t Or, 20t=1600 or, t=80 hours Ans. (E) _________________ Regards, PKN Rise above the storm, you will find the sunshine Manager Joined: 01 Feb 2018 Posts: 96 Location: India GMAT 1: 700 Q47 V38 WE: Consulting (Consulting) Re: Every week, Renee is paid$40 per hour for the first 40 hours she work  [#permalink]

### Show Tags

26 Aug 2018, 22:22
1
PKN wrote:
Bunuel wrote:
Every week, Renee is paid $40 per hour for the first 40 hours she works, and$80 per hour for each hour she works after the first 40 hours. How many hours would Renee have to work in one week to earn an average (arithmetic mean) of $60 per hour that week? (A) 60 (B) 65 (C) 70 (D) 75 (E) 80 Renee makes$40*40 hours=$1600 in first 40 hours Let 't' be the no of hours Renee would work. Given, Renee makes$80 per hour for each hour she works after the first 40 hours. So, she makes an additional pay $80*(t-40)hours for every hour after 40 hours. So, $$\frac{1600+80(t-40)}{t}=60$$ Or, 1600+80t-3200=60t Or, 20t=1600 or, t=80 hours Ans. (E) PKN Hi, Could you explain this part " So, she makes an additional pay$80*(t-40)hours for every hour after 40 hours.".
The way I was looking at it was:
Let x be the extra hours worked,
so to make the average equal to 60,
In the first 40 hours, amount earned = 1600.
Next x hours, amount earned = 80x (Since per hour = $80 after first 40 hrs) (1600 +80x) / (40 + x) = 60 But on solving this I get 20x = 800 and x = 40 which is not in the options. Could you please explain where am I going wrong? Thanks a lot. _________________ Please press Kudos if this helped “Going in one more round when you don't think you can, that's what makes all the difference in your life.” VP Status: Learning stage Joined: 01 Oct 2017 Posts: 1011 WE: Supply Chain Management (Energy and Utilities) Re: Every week, Renee is paid$40 per hour for the first 40 hours she work  [#permalink]

### Show Tags

26 Aug 2018, 22:29
1
Sreyoshi007 wrote:
PKN wrote:
Bunuel wrote:
Every week, Renee is paid $40 per hour for the first 40 hours she works, and$80 per hour for each hour she works after the first 40 hours. How many hours would Renee have to work in one week to earn an average (arithmetic mean) of $60 per hour that week? (A) 60 (B) 65 (C) 70 (D) 75 (E) 80 Renee makes$40*40 hours=$1600 in first 40 hours Let 't' be the no of hours Renee would work. Given, Renee makes$80 per hour for each hour she works after the first 40 hours. So, she makes an additional pay $80*(t-40)hours for every hour after 40 hours. So, $$\frac{1600+80(t-40)}{t}=60$$ Or, 1600+80t-3200=60t Or, 20t=1600 or, t=80 hours Ans. (E) PKN Hi, Could you explain this part " So, she makes an additional pay$80*(t-40)hours for every hour after 40 hours.".
The way I was looking at it was:
Let x be the extra hours worked,
so to make the average equal to 60,
In the first 40 hours, amount earned = 1600.
Next x hours, amount earned = 80x (Since per hour = $80 after first 40 hrs) (1600 +80x) / (40 + x) = 60 But on solving this I get 20x = 800 and x = 40 which is not in the options. Could you please explain where am I going wrong? Thanks a lot. Hi Sreyoshi007, You are absolutely correct. Your x=No of additional hours=40. Question stem:-How many hours would Renee have to work in one week to earn an average (arithmetic mean) of$60 per hour that week. ALREADY SHE HAS WORKED FOR 40 HOURS.

So, total no of hours she would work in a week=first 40 hours+additional hours=40+x=40+40=80

Hope it helps.
_________________
Regards,

PKN

Rise above the storm, you will find the sunshine
Manager
Joined: 01 Feb 2018
Posts: 96
Location: India
GMAT 1: 700 Q47 V38
WE: Consulting (Consulting)
Re: Every week, Renee is paid $40 per hour for the first 40 hours she work [#permalink] ### Show Tags 26 Aug 2018, 22:35 Quote: Hi Sreyoshi007, You are absolutely correct. Your x=No of additional hours=40. Question stem:-How many hours would Renee have to work in one week to earn an average (arithmetic mean) of$60 per hour that week. ALREADY SHE HAS WORKED FOR 40 HOURS.

So, total no of hours she would work in a week=first 40 hours+additional hours=40+x=40+40=80

Hope it helps.

PKN Thanks a lot, I got it now. I should have re-read the question stem more carefully.
_________________
Please press Kudos if this helped

“Going in one more round when you don't think you can, that's what makes all the difference in your life.”
VP
Status: Learning stage
Joined: 01 Oct 2017
Posts: 1011
WE: Supply Chain Management (Energy and Utilities)
Re: Every week, Renee is paid $40 per hour for the first 40 hours she work [#permalink] ### Show Tags 26 Aug 2018, 23:29 1 Sreyoshi007 wrote: Quote: Hi Sreyoshi007, You are absolutely correct. Your x=No of additional hours=40. Question stem:-How many hours would Renee have to work in one week to earn an average (arithmetic mean) of$60 per hour that week. ALREADY SHE HAS WORKED FOR 40 HOURS.

So, total no of hours she would work in a week=first 40 hours+additional hours=40+x=40+40=80

Hope it helps.

PKN Thanks a lot, I got it now. I should have re-read the question stem more carefully.

You are welcome Sreyoshi007,

I would suggest, there are two ways you can avoid these kind of situations.
1) Write down the question stem at first glance. (WHAT IS ASKED or WHAT IS OUR REQUIREMENT)
2) Always try to assign the variable to your requirement. (For example, here our requirement was "total no of hours". So, assign x or t =Total no of hours)
Merit:- After solving, the value of the variable would direct you to the correct answer option.
_________________
Regards,

PKN

Rise above the storm, you will find the sunshine