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 2308:00 PM PDT
-09:00 PM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
Apr 2301:30 AM EDT
-02:30 AM EDT
Struggling with GMAT Verbal as a non-native speaker? Harsh improved his score from 595 to 695 in just 45 days—and scored a 99 %ile in Verbal (V88)! Learn how smart strategy, clarity, and guided prep helped him gain 100 points.
Apr 2512:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
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.
04 Jul 2018, 00:08
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
90% (01:00) correct
10%
(01:17)
wrong
based on 1366
sessions
History
Date
Time
Result
Not Attempted Yet
A flower arrangement consists of 30 roses, each of which is either white or red. If a rose is to be selected at random from the flower arrangement, the probability that the rose selected will be white is twice the probability that it will be red. How many white roses are in the flower arrangement?
A. 5
B. 10
C. 15
D. 20
E. 25
A. 5
B. 10
C. 15
D. 20
E. 25
If this question felt shaky,
try an adaptive mini quiz of similar problems in
GMAT Club Forum Quiz →. Free plan gives 5 questions per day.
Ans: D
Easiest way:
P(w) = 2P(r)
because there are only red and white roses that means total of 30 roses are divided between White and Red in 2:1 (only then P(w) can be twice the P(r)
so White roses = 2 * 30/3 = 20
Another way to say the same
Given that total roses =30
P(w)=2P(r)
We know there are only white or red roses so P(w)+P(r)=1
so 3P(r)=1 ; P(r) =1/3 this mean P(w) = 2/3 = 20/30 where 30 is the total outcome and 20 will be the favourable outcomes.
no. of white roses = 20
Easiest way:
P(w) = 2P(r)
because there are only red and white roses that means total of 30 roses are divided between White and Red in 2:1 (only then P(w) can be twice the P(r)
so White roses = 2 * 30/3 = 20
Another way to say the same
Given that total roses =30
P(w)=2P(r)
We know there are only white or red roses so P(w)+P(r)=1
so 3P(r)=1 ; P(r) =1/3 this mean P(w) = 2/3 = 20/30 where 30 is the total outcome and 20 will be the favourable outcomes.
no. of white roses = 20
05 Jul 2018, 04:01
Kudos
Bookmarks
Solution
Given:
- • Total number of roses in the flower arrangement = 30
• Each rose is either white or red in color
• A rose is randomly selected from the arrangement
• The probability that the selected rose will be white = 2 * the probability that the selected rose will be red
To find:
- • Number of white roses in the arrangement
Approach and Working:
- • Assume the probability of the selected rose will be white as P(w), and the probability of the selected rose will be red as P(r)
• P(r) + P(w) = 1, and ……………………………………. (1)
• Also given, P(w) = 2 * P(r) …………………………... (2)
• From (1) and (2), we get
- o P(r) = \(\frac{1}{3}\) and P(w) = \(\frac{2}{3}\)
• Therefore, the number of white roses in the arrangement = \(\frac{2}{3} *\) total number of roses
• Thus, number of white roses = \(\frac{2}{3} * 30\) = 20
Hence, the correct answer is option D.
Answer: D
