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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

abcd ≠ 0, a:b:c = 2:3:4, c:d = 5:6, and a + b + c – d =

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 amFollowed by: 37 members
Location: Las Vegas, USA
Thanked: 19 times
by Max@Math Revolution » Thu May 30, 2019 12:25 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

[GMAT math practice question]

abcd ≠ 0, a:b:c = 2:3:4, c:d = 5:6, and a + b + c - d = 42. What is the value of d?

A. 6
B. 12
C. 24
D. 36
E. 48
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 amFollowed by: 37 members
Location: Las Vegas, USA
Thanked: 19 times

by Max@Math Revolution » Sun Jun 02, 2019 4:50 pm
=>

We combine the ratios to form a single ratio for a:b:c:d as follows:
a : b : c = 2 : 3 : 4
c : d = 5 : 6

Multiplying both equations by 5 yields

a : b : c = 10 : 15 : 20
c : d = 20 : 24

and combining them to form a single ratio gives
a : b : c : d = 10 : 15 : 20 : 24

Thus, a = 10k, b = 15k, c = 20k, d = 24k for some number k.
Substituting these values into the expression for a + b + c - d yields
a + b + c - d = 10k + 15k + 20k - 24k = 21k = 42.
Thus, k = 2 and d = 24k = 48.

Therefore, the answer is E.
Answer: E
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1