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

 It is currently 20 Oct 2019, 20:12

### 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

### Show Tags

03 Jan 2011, 18:22
10
00:00

Difficulty:

75% (hard)

Question Stats:

60% (02:32) correct 40% (02:34) wrong based on 359 sessions

### HideShow timer Statistics

The toll for crossing a certain bridge is $0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for$13.00 and then pay only $0.30 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker? A. 14 B. 15 C. 16 D. 28 E. 29 ##### Most Helpful Expert Reply Math Expert Joined: 02 Sep 2009 Posts: 58434 Re: The toll for crossing a certain bridge [#permalink] ### Show Tags 04 Jan 2011, 03:50 5 6 ajit257 wrote: The toll for crossing a certain bridge is$0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for $13.00 and then pay only$0.30 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker?
A. 14
B. 15
C. 16
D. 28
E. 29

Cost for the driver for 2x (twice on each of x days) crosses without the sticker will be: $$2x*0.75$$;
Cost for the driver for 2x (twice on each of x days) crosses with the sticker will be: $$13+2x*0.3$$;

Question: what is the least value of $$x$$ for which $$13+2x*0.3<2x*0.75$$ --> $$x>14.4$$ --> $$x_{min}=15$$.

_________________
##### General Discussion
Manager
Joined: 21 Jul 2010
Posts: 51
Re: The toll for crossing a certain bridge  [#permalink]

### Show Tags

04 Jan 2011, 01:03
1
I don't get this one. I would do for D. I plugged the number of the OA in my equation but it does not work for me.

Anyone?
Intern
Joined: 21 Sep 2010
Posts: 16
Re: The toll for crossing a certain bridge  [#permalink]

### Show Tags

04 Jan 2011, 09:16
1
Savings per crossings = 0.45 (.75-.30)

Saving per crossing x 2 times (crossing bothways) x Number of days >= $13 (.45)2x>=13 .9x>=13 x>14.44 Xmin =15 days Manager Joined: 18 Oct 2011 Posts: 78 Location: United States Concentration: Entrepreneurship, Marketing GMAT Date: 01-30-2013 GPA: 3.3 Re: Arithematic [#permalink] ### Show Tags 11 Feb 2013, 19:19 1 Option #1:$0.75/crossing....Cross twice a day = $1.5/day Option #2:$0.30/crossing....Cross twice a day = $0.6/day +$13 one time charge.

If we go down the list of possible answers, you can quickly see that 14 days will not be worth purchasing the sticker. 1.5x14 (21) is cheaper than 0.6x14 +13 (21.4)...it's pretty close so let's see if one more day will make it worth it... If we raise the number of days to 15, the sticker option looks like a better deal...1.5x15 (22.5) vs 0.6x15 + 13 (22). Answer: B
Verbal Forum Moderator
Joined: 10 Oct 2012
Posts: 590

### Show Tags

11 Feb 2013, 22:59
For the given condition,

$$0.3*2*x+13<0.75*x*2$$

or

$$0.6*x+13<1.5*x$$

or $$0.9*x>13$$

$$x>130*0.11$$ = 14.3

Thus x = 15.

B.
_________________
Manager
Joined: 30 Mar 2013
Posts: 101

### Show Tags

24 Jan 2018, 10:40
ajit257 wrote:
The toll for crossing a certain bridge is $0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for$13.00 and then pay only $0.30 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker? A. 14 B. 15 C. 16 D. 28 E. 29 We can create the following inequality: 0.75(2x) > 13 + 0.3(2x) 1.5x > 13 + 0.6x 0.9x > 13 x > 13/0.9 x > 130/9 x > 14 4/9 So the minimum value of x is 15. Answer: B _________________ # Jeffrey Miller Head of GMAT Instruction Jeff@TargetTestPrep.com 122 Reviews 5-star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button. Non-Human User Joined: 09 Sep 2013 Posts: 13318 Re: The toll for crossing a certain bridge is$0.75 each crossin  [#permalink]

### Show Tags

20 May 2019, 18:36
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________