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 →

Johnson has a corporate proposal. The probability that vice

Expert replies
Post new topic Post Reply
Previous Topic Next Topic

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 768
Joined: Wed Dec 28, 2011 4:18 pmFollowed by: 140 members
Location: Berkeley, CA
Thanked: 387 times
by Mike@Magoosh » Fri Jan 03, 2014 5:47 pm
The following information accompanies questions 6-7

Johnson has a corporate proposal. The probability that vice-president Adams will approve the proposal is 0.6. If VP Adams approves the proposal, then the probability that vice-president Baker will approve the proposal is 0.8. If VP Adams doesn't approve the proposal, then the probability that vice-president Baker will approve the proposal is 0.3.

6) What is the probability that one of the two VPs, but not the other, approves Johnson's proposal?
(A) 0.12
(B) 0.24
(C) 0.28
(D) 0.48
(E) 0.72

7) What is the probability that at least one of the two VPs, approves Johnson's proposal?
(A) 0.12
(B) 0.24
(C) 0.28
(D) 0.48
(E) 0.72

These two questions are paired to raise the subtle question: do they have the same answer? why or why not? How do we calculate them? For a full discussion of tricky probability questions, as well as the OA & OE for these, see:
https://magoosh.com/gmat/2014/gmat-advan ... -problems/

Mike :-)
Magoosh GMAT Instructor
https://gmat.magoosh.com/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Sun Feb 24, 2013 2:29 am
Location: Belgrade
Thanked: 1 times

by Milovan » Thu Jan 09, 2014 12:31 pm
Firstly I would create a little recap of the info we have:

P (Adams approves) = 0.6 -> P (Baker approves) = 0.8
P (Baker reject) = 0.2

P (Adams reject) = 0.4 -> P (Baker approves) = 0.3
P (Baker rejects) = 0.7

6) We have two combinations: 1. Adams approves and Baker rejects
2. Adams rejects and Baker approves

P (1. or 2.) = P(1.) + P(2.) - each P(1.) and P(2.) has two dependent cases (approves - rejects and rejects - approves) so we use multiplication between them.

P (1. or 2.) = 0,6 * 0,2 + 0,4 * 0,3 = 0,24 and the answer is B


7) As soon as we see At least we should think about P(good) = 1 - P(bad)
P (at least one approval) = 1 - P(both reject) = 1 - 0,4 * 0,7 = 0,72

The correct answer is E
Milovan Arnaut
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1