GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 03 Aug 2020, 19:03 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  # If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the

Author Message
Intern  B
Joined: 20 May 2020
Posts: 3
If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the  [#permalink]

### Show Tags 00:00

Difficulty:   25% (medium)

Question Stats: 92% (01:45) correct 8% (01:47) wrong based on 12 sessions

### HideShow timer Statistics

If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the sum equals 350, which of the following could be equal to n ?

A. 38
B. 39
C. 40
D. 41
E. 42
GMAT Tutor S
Joined: 16 Sep 2014
Posts: 554
Location: United States
GMAT 1: 780 Q51 V45
GRE 1: Q170 V167
Re: If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the  [#permalink]

### Show Tags

1
vpsu wrote:
If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the sum equals 350, which of the following could be equal to n ?

A. 38
B. 39
C. 40
D. 41
E. 42

We can make a table of the number of 7's and 77's needed to build up to 350. Note that we have to exchange one 77 for eleven 7's.

Let's start with the base case of 50 * 7 = 350. Then we can also have 39*7 + 1*77 = 350, or 28*7 + 2*77 = 350. The total number of terms will drop by 10 for every additional 77 becasue +1 - 11 = -10.

Thus our possible answers for the number of terms are 50, 40, 30, 20, and 10.

Ans: C
_________________
Source: We are an NYC based, in-person and online GMAT tutoring and prep company. We are the only GMAT provider in the world to guarantee specific GMAT scores with our flat-fee tutoring packages, or to publish student score increase rates. Our typical new-to-GMAT student score increase rate is 3-9 points per tutoring hour, the fastest in the world. Feel free to reach out!
Math Expert V
Joined: 02 Sep 2009
Posts: 65765
Re: If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the  [#permalink]

### Show Tags

vpsu wrote:
If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the sum equals 350, which of the following could be equal to n ?

A. 38
B. 39
C. 40
D. 41
E. 42

This question is discussed here: https://gmatclub.com/forum/if-each-term ... 93974.html In case of questions please post there. Hope it helps.

THIS TOPIC IS LOCKED AND ARCHIVED.
_________________ Re: If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the   [#permalink] 14 Jul 2020, 21:17

# If each term in the sum a1 + a2 + ... + an is either 7 or 77 and the  