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

 It is currently 17 Feb 2019, 10:18

### 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

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT Algebra Webinar

February 17, 2019

February 17, 2019

07:00 AM PST

09:00 AM PST

Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
• ### Valentine's day SALE is on! 25% off.

February 18, 2019

February 18, 2019

10:00 PM PST

11:00 PM PST

We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

# John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar

Author Message
TAGS:

### Hide Tags

Manager
Joined: 14 Apr 2010
Posts: 177
John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

04 Aug 2010, 23:13
2
00:00

Difficulty:

25% (medium)

Question Stats:

77% (01:19) correct 23% (01:55) wrong based on 101 sessions

### HideShow timer Statistics

John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar bills. If John needs to pay exactly \$128, what is the least number of bills he will need to use?

A. 14
B. 16
C. 17
D. 19
E. 20
Manager
Joined: 18 Feb 2010
Posts: 151
Schools: ISB
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

04 Aug 2010, 23:16
1
1
bibha wrote:
John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar bills. If John needs to pay exactly \$128, what is the least number of bills he will need to use?
14
16
17
19
20

10*12 + 5*1 + 1*3 = 128

Therefore the answer is 16 (B)
_________________

CONSIDER AWARDING KUDOS IF MY POST HELPS !!!

Manager
Joined: 14 Apr 2010
Posts: 177
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

05 Aug 2010, 01:20
I know....but how do you decide thjat?
Manager
Joined: 16 Apr 2010
Posts: 199
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

05 Aug 2010, 01:58
1
It is simple.

To minimize the number of bills you have to pay with the highest value of bill.
Since the amount is 128, you cannot pay with 13 10\$ bills, but you can with 12 10\$ bills.
Now that you've paid 120\$. You have to pay the rest (8\$) in 5\$ and 1\$ bills. Again to minimize the number of bills that you are gonna use, you have to maximize the number of 5\$ bills you can use to pay the 8\$. In this case it is 1 5\$ bill.

Hope this is clear to you now.
Senior Manager
Status: Fighting on
Joined: 14 Mar 2010
Posts: 284
WE 1: SE - 1
WE 2: Engineer - 3
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

05 Aug 2010, 07:04
128 is the total sum of money.

as we have 13 10 dollar bills so the closest we can get to 128 using the 10 dollar bills is by using 12 * 10 dollar bils

128-120 = 8

so now we need to get 8 from either 5 dollar bills or 1 dollar bills

8 - 5 (use only 1 5 dollar bill) = 3

so we can get 3 from using 3 \$1 bills.

Hence 16 ( 12+1+3 )
Non-Human User
Joined: 09 Sep 2013
Posts: 9836
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar  [#permalink]

### Show Tags

13 Oct 2018, 21:32
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.
_________________
Re: John has 13 ten-dollar bills, 11 five-dollar bills, and 17 one-dollar   [#permalink] 13 Oct 2018, 21:32
Display posts from previous: Sort by