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

 It is currently 16 Dec 2019, 00:03

### 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

# If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra

Author Message
TAGS:

### Hide Tags

Manager
Joined: 08 May 2015
Posts: 86
GMAT 1: 630 Q39 V38
GMAT 2: 670 Q44 V38
GMAT 3: 750 Q49 V44
If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

20 Jul 2015, 13:41
1
00:00

Difficulty:

35% (medium)

Question Stats:

60% (00:59) correct 40% (02:15) wrong based on 11 sessions

### HideShow timer Statistics

If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the range of the possible values for $$\frac{a}{b}$$?

A) $$\frac{12}{19}$$
B) $$\frac{120}{589}$$
C) $$\frac{12}{31}$$
D) $$\frac{2}{3}$$
E) $$\frac{480}{589}$$
CEO
Joined: 20 Mar 2014
Posts: 2560
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

20 Jul 2015, 14:13
Mascarfi wrote:
If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the range of the possible values for $$\frac{a}{b}$$?

A) $$\frac{12}{19}$$
B) $$\frac{120}{589}$$
C) $$\frac{12}{31}$$
D) $$\frac{2}{3}$$
E) $$\frac{480}{589}$$

How can range of possible values be just 1 value? Please check the question again.
Manager
Joined: 08 May 2015
Posts: 86
GMAT 1: 630 Q39 V38
GMAT 2: 670 Q44 V38
GMAT 3: 750 Q49 V44
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

20 Jul 2015, 14:29
I thaught the same, thats why i put it here. A trap i have not yet found...

You have that they are integers, so the biggest possible value for a/b is the biggest value of a divided by the smallest value of b...20/20 = 1

...the smallest possible value for a/b is the smallest value of a divided by the biggest value of b...10/30= 1/3...

Then you have:

1 - (1/3) = 2/3
CEO
Joined: 20 Mar 2014
Posts: 2560
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

20 Jul 2015, 14:36
Mascarfi wrote:
I thaught the same, thats why i put it here. A trap i have not yet found...

You have that they are integers, so the biggest possible value for a/b is the biggest value of a divided by the smallest value of b...20/20 = 1

...the smallest possible value for a/b is the smallest value of a divided by the biggest value of b...10/30= 1/3...

Then you have:

1 - (1/3) = 2/3

Ok . It makes sense now. I was too quick to jump the gun there. 2/3 does seem logical to me.
Current Student
Joined: 22 Apr 2015
Posts: 44
Location: United States
GMAT 1: 620 Q46 V27
GPA: 3.86
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

20 Jul 2015, 15:22
1
Range: Largest-Smallest

The largest number would have largest A value and smallest B value

A=20 B=20

20/20=1

Smallest value: smallest A value and largest B value
A=10 B= 30

1-(10/30)

30-10/30=20/30=2/3
Senior Manager
Joined: 28 Jun 2015
Posts: 279
Concentration: Finance
GPA: 3.5
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra  [#permalink]

### Show Tags

21 Jul 2015, 08:47
$$Range = Maximum(\frac{a}{b}) - Minimum(\frac{a}{b})$$

$$Maximum(\frac{a}{b})$$ is when $$a$$ is maximum and $$b$$ is minimum = $$\frac{20}{20} = 1$$.

$$Minimum(\frac{a}{b})$$ is when $$a$$ is minimum and $$b$$ is maximum = $$\frac{10}{30} = \frac{1}{3}$$.

Range = $$1 - \frac{1}{3} = \frac{2}{3}$$. Ans (D).
_________________
I used to think the brain was the most important organ. Then I thought, look what’s telling me that.
Re: If a and b are integers and 9 < a < 21 and 19 < b < 31, what is the ra   [#permalink] 21 Jul 2015, 08:47
Display posts from previous: Sort by