Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
05 Jan 2021, 07:17
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
61% (02:00) correct
39%
(02:13)
wrong
based on 159
sessions
History
Date
Time
Result
Not Attempted Yet
A student must choose exactly two out of the three following electives: art, French, mathematics. He chooses art with probability 5/8, French with probability 5/8, and art and French together with probability 1/4. What is the probability that he chooses mathematics?
A. 1/4
B. 1/3
C. 1/2
D. 3/4
E. 1
A. 1/4
B. 1/3
C. 1/2
D. 3/4
E. 1
Updated on: 05 Jan 2021, 08:03
Originally posted by BrentGMATPrepNow on 05 Jan 2021, 07:59.
Last edited by BrentGMATPrepNow on 05 Jan 2021, 08:03, edited 1 time in total.
Last edited by BrentGMATPrepNow on 05 Jan 2021, 08:03, edited 1 time in total.
Kudos
Bookmarks
Bunuel
P(does NOT choose math) = P(chooses Art and French)
= 1/4
P(DOES choose math) = 1 - P(does NOT choose math)
1 - 1/4
= 3/4
Answer: D
General Discussion
05 Jan 2021, 08:00
Kudos
Bookmarks
There are 3 scenarios that can chosen only:
French + Art
French + Math
Math + Art
(A) Overall Probability that he chooses Art as 1 of the 2
= (Prob he chooses French + Art) + (Prob he chooses Math + Art) = 5/8
(B) Overall Prob that he chooses French as 1 of the 2
= (Prob he chooses Art + French) + (Prob he chooses Math + French) = 5/8
(C) And we are given that the Prob he chooses Exactly Art + French = 1/4
We need to find the Prob he chooses Math, which is found by calculating the following:
Prob he chooses Math = (Prob he chooses Math + Art) + (Prob he chooses Math + French)
(1st) Prob he chooses Math + Art =
(Overall Prob he chooses Art) - (Prob he chooses Art + French)
This equals:
(5/8) - (1/4) = 3/8
2nd) Prob he chooses Math + French =
(overall Prob he chooses French) - (Prob he chooses Art + French)
(5/8) - (1/4) = 3/8
(3rd)Solution
Overall Prob he chooses Math as 1 of the 2 =
[ (3/8) Prob he chooses Math + Art ]
+
[ (3/8) Prob he chooses Math + French ]
=
6/8 = 3/4
D
Posted from my mobile device
French + Art
French + Math
Math + Art
(A) Overall Probability that he chooses Art as 1 of the 2
= (Prob he chooses French + Art) + (Prob he chooses Math + Art) = 5/8
(B) Overall Prob that he chooses French as 1 of the 2
= (Prob he chooses Art + French) + (Prob he chooses Math + French) = 5/8
(C) And we are given that the Prob he chooses Exactly Art + French = 1/4
We need to find the Prob he chooses Math, which is found by calculating the following:
Prob he chooses Math = (Prob he chooses Math + Art) + (Prob he chooses Math + French)
(1st) Prob he chooses Math + Art =
(Overall Prob he chooses Art) - (Prob he chooses Art + French)
This equals:
(5/8) - (1/4) = 3/8
2nd) Prob he chooses Math + French =
(overall Prob he chooses French) - (Prob he chooses Art + French)
(5/8) - (1/4) = 3/8
(3rd)Solution
Overall Prob he chooses Math as 1 of the 2 =
[ (3/8) Prob he chooses Math + Art ]
+
[ (3/8) Prob he chooses Math + French ]
=
6/8 = 3/4
D
Posted from my mobile device
