BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

If the product of the integers a, b, c, and d is

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 2058
Joined: Sun Oct 29, 2017 4:24 am
Thanked: 1 times
Followed by:5 members

If the product of the integers a, b, c, and d is

by M7MBA » Sun Feb 18, 2018 4:48 am
If the product of the integers a, b, c, and d is 1,155 and if a > b > c > d > 1, then what is the value of a - d?

(A) 2
(B) 8
(C) 10
(D) 11
(E) 14

The OA is the option B.

How can I determine the value of a, b, c and d? What is the best approach to finding them? Experts, can you help me?
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Sun Feb 18, 2018 10:45 am
Hi M7MBA,

We're told that the product of the integers A, B, C and D is 1,155 and A > B > C > D > 1. We're asked for the value of A - D. This question comes down to 'prime factorization' and a bit of Arithmetic.

We know that the 4 variables are INTEGERS and we know that they are DIFFERENT from one another. To define those values, we have to 'break down' the product (1155) into its pieces.

1155 =
(5)(231) =
(5)(3)(77) =
(5)(3)(7)(11)

Given the inequality... A=11, B=7, C=5 and D=3... so (A - D) = (11 - 3) = 8

Final Answer: B

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
User avatar
GMAT Instructor
Posts: 1462
Joined: Thu Apr 09, 2015 9:34 am
Location: New York, NY
Thanked: 39 times
Followed by:22 members

by Jeff@TargetTestPrep » Wed Feb 21, 2018 1:40 pm
M7MBA wrote:If the product of the integers a, b, c, and d is 1,155 and if a > b > c > d > 1, then what is the value of a - d?

(A) 2
(B) 8
(C) 10
(D) 11
(E) 14
We can start by expressing 1,155 as the product of its prime factors.

1,155 = 5 x 231 = 5 x 77 x 3 = 5 x 7 x 11 x 3

This means that a = 11, b = 7, c = 5, and d = 3.

Thus, a - d = 11 - 3 = 8.

Answer: B

Jeffrey Miller
Head of GMAT Instruction
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
Top
Post new topic Post Reply
• Page 1 of 1