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

 It is currently 18 Nov 2018, 08:38

### 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 November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• ### How to QUICKLY Solve GMAT Questions - GMAT Club Chat

November 20, 2018

November 20, 2018

09:00 AM PST

10:00 AM PST

The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.
• ### The winning strategy for 700+ on the GMAT

November 20, 2018

November 20, 2018

06:00 PM EST

07:00 PM EST

What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

# If m and n are positive integers, what is the value of m + n?

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6517
GMAT 1: 760 Q51 V42
GPA: 3.82
If m and n are positive integers, what is the value of m + n?  [#permalink]

### Show Tags

19 Jul 2018, 01:27
00:00

Difficulty:

35% (medium)

Question Stats:

65% (00:41) correct 35% (01:19) wrong based on 51 sessions

### HideShow timer Statistics

[GMAT math practice question]

If $$m$$ and $$n$$ are positive integers, what is the value of $$m + n$$?

$$1) m^2< 5$$
$$2) m – n = 1$$

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course" "Free Resources-30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons - try it yourself" PS Forum Moderator Joined: 25 Feb 2013 Posts: 1217 Location: India GPA: 3.82 If m and n are positive integers, what is the value of m + n? [#permalink] ### Show Tags 19 Jul 2018, 01:36 MathRevolution wrote: [GMAT math practice question] If $$m$$ and $$n$$ are positive integers, what is the value of $$m + n$$? $$1) m^2< 5$$ $$2) m – n = 1$$ Statement 1: Nothing mentioned about $$n$$. $$m$$ can be $$1$$ or $$2$$. Insufficient Statement 2: two variables and one equation, cannot be solved. Insufficient Combining 1 & 2: $$m$$ cannot be $$1$$, because in that case $$n=0$$ which is not possible as it is a positive integer. Hence $$m=2$$ & $$n=1$$. Therefore $$m+n=3$$. Sufficient Option C Director Joined: 20 Feb 2015 Posts: 796 Concentration: Strategy, General Management Re: If m and n are positive integers, what is the value of m + n? [#permalink] ### Show Tags 19 Jul 2018, 02:24 MathRevolution wrote: [GMAT math practice question] If $$m$$ and $$n$$ are positive integers, what is the value of $$m + n$$? $$1) m^2< 5$$ $$2) m – n = 1$$ 1.m^2 < 5 m can be 1,2 n=? insufficient 2.m-n=1 insufficient combining both m=2 and n=1 m+n=3 Therefore, C Senior Manager Joined: 04 Aug 2010 Posts: 307 Schools: Dartmouth College Re: If m and n are positive integers, what is the value of m + n? [#permalink] ### Show Tags 19 Jul 2018, 02:29 MathRevolution wrote: [GMAT math practice question] If $$m$$ and $$n$$ are positive integers, what is the value of $$m + n$$? $$1) m^2< 5$$ $$2) m – n = 1$$ Statement 1: Since m must be a positive integer, only two cases are possible: Case 1: m=1, with the result that m² = 1 Case 2: m=2, with the result that m² = 4 Since the value of n is unknown, INSUFFICIENT. Statement 2: m = n+1 Case 1: n=1, with the result that m=2 and m+n = 3 Case 2: n=2, with the result that m=3 and m+n = 5 Since m+n can be different values, INSUFFICIENT. Statements combined: Only the case in blue satisfies both statements. Thus, m+n = 3. SUFFICIENT. _________________ GMAT and GRE Tutor Over 1800 followers Click here to learn more GMATGuruNY@gmail.com New York, NY If you find one of my posts helpful, please take a moment to click on the "Kudos" icon. Available for tutoring in NYC and long-distance. For more information, please email me at GMATGuruNY@gmail.com. Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 6517 GMAT 1: 760 Q51 V42 GPA: 3.82 Re: If m and n are positive integers, what is the value of m + n? [#permalink] ### Show Tags 22 Jul 2018, 17:14 => Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution. Since we have 2 variables (m and n) and 0 equations, C is most likely to be the answer. So, we should consider conditions 1) & 2) together first. After comparing the number of variables and the number of equations, we can save time by considering conditions 1) & 2) together first. Conditions 1) & 2) Condition 1) tells us that m = 1 or m = 2. If m = 1, then n = 1 – 1 = 0, which is not a positive integer. If m = 2, then n = 2 - 1 = 1. Thus, the unique values are m = 2 and n = 1, and m + n = 3. Both conditions together are sufficient. Since this question is an integer question (one of the key question areas), CMT (Common Mistake Type) 4(A) of the VA (Variable Approach) method tells us that we should also check answers A and B. Condition 1) Since it provides no information about the variable n, condition 1) is not sufficient. Condition 2) If m = 2 and n = 1, then m + n = 3. If m = 3 and n = 2, then m + n = 5. Since we don’t have a unique solution, condition 2) is not sufficient. Therefore, C is the answer. Answer: C Normally, in problems which require 2 equations, such as those in which the original conditions include 2 variables, or 3 variables and 1 equation, or 4 variables and 2 equations, each of conditions 1) and 2) provide an additional equation. In these problems, the two key possibilities are that C is the answer (with probability 70%), and E is the answer (with probability 25%). Thus, there is only a 5% chance that A, B or D is the answer. This occurs in common mistake types 3 and 4. Since C (both conditions together are sufficient) is the most likely answer, we save time by first checking whether conditions 1) and 2) are sufficient, when taken together. Obviously, there may be cases in which the answer is A, B, D or E, but if conditions 1) and 2) are NOT sufficient when taken together, the answer must be E. _________________ MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only$99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Re: If m and n are positive integers, what is the value of m + n? &nbs [#permalink] 22 Jul 2018, 17:14
Display posts from previous: Sort by