Of the integers between 100 and 799, inclusive

Expert replies

Previous Topic Next Topic

VJesus12: Legendary Member; Posts: 2276; Joined: Sat Oct 14, 2017 6:10 amFollowed by: 3 members

by VJesus12 » Thu Jun 28, 2018 5:15 am

Timer

00:00

Answers

Stats

Difficulty—

Of the integers between 100 and 799, inclusive, how many do not have digit 2 and 5?

(A) 310
(B) 320
(C) 410
(D) 420
(E) 520

The OA is the option B.

Is there a fast way to solving this PS question? I don't have any good idea.

Please, someone, help me. <i class="em em-disappointed"></i>

Like this post

Source: Beat The GMAT — Problem Solving | Thu Jun 28, 2018 5:15 am

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Thu Jun 28, 2018 5:23 am

VJesus12 wrote:Of the integers between 100 and 799, inclusive, how many do not have digit 2 and 5?

(A) 310
(B) 320
(C) 410
(D) 420
(E) 520

Number of options for the hundreds digit = 5. (Of the seven digits 1-7, any but 2 or 5.)
Number of options for the tens digit = 8. (Of the ten digits 0-9, any but 2 or 5.)
Number of options for the units digit = 8. (Of the ten digits 0-9, any but 2 or 5.)
To combine these options, we multiply:
5*8*8 = 320.

The correct answer is B.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Like this post

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8178; Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members; Location: Los Angeles, CA; Thanked: 43 times

by Scott@TargetTestPrep » Mon Apr 29, 2019 8:09 am

VJesus12 wrote:Of the integers between 100 and 799, inclusive, how many do not have digit 2 and 5?

(A) 310
(B) 320
(C) 410
(D) 420
(E) 520

The OA is the option B.

Is there a fast way to solving this PS question? I don't have any good idea.

Please, someone, help me. <i class="em em-disappointed"></i>

Let's start with the hundreds digit; we have 5 choices (1, 3, 4, 6, 7). Each of the tens and units digits has 8 choices (any of the 10 digits except 2 and 5). Thus, there are 5 x 8 x 8 = 320 numbers that do not contain 2 and 5.

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review