|
|
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.
07 Apr 2022, 08:15
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
71% (01:58) correct
29%
(02:31)
wrong
based on 73
sessions
History
Date
Time
Result
Not Attempted Yet
In a mixture of lead and tin, there is 57% tin. How much lead must be added to 100 kg of this mixture to reduce the percentage of tin in the new mixture to 38%?
(A) 20 kg
(B) 40 kg
(C) 50 kg
(D) 60 kg
(E) 70 kg
(A) 20 kg
(B) 40 kg
(C) 50 kg
(D) 60 kg
(E) 70 kg
11 Apr 2022, 11:59
Kudos
Bookmarks
This is a fairly straight forward question, testing your conceptual knowledge of percentages and fractions.
As per the question, a mixture of lead and tin has 57% tin; therefore, the percentage of lead is 43.
It is given that there is 100 kg of this mixture. Therefore,
Weight of tin in the mixture = 57% of 100 = 57 kg
Weight of lead in the mixture = 43% of 100 = 43 kg
A certain quantity of lead is being added to this mixture. Let this quantity of lead being added be x kg.
As a result of the addition of x kg of lead, the percentage of lead increases while that of tin reduces to 38%. This means that the resultant percentage of lead is 62%, which also means that tin and lead are now in the ratio of 38:62 OR 19:31, respectively.
Therefore,
\(\frac{57 }{ (43 + x)}\) = \(\frac{19 }{ 31}\)
Simplifying and solving the above equation, x = 50.
50 kg of lead should be added to the 100kg mixture to reduce the percentage of tin to 38%.
The correct answer option is C.
As per the question, a mixture of lead and tin has 57% tin; therefore, the percentage of lead is 43.
It is given that there is 100 kg of this mixture. Therefore,
Weight of tin in the mixture = 57% of 100 = 57 kg
Weight of lead in the mixture = 43% of 100 = 43 kg
A certain quantity of lead is being added to this mixture. Let this quantity of lead being added be x kg.
As a result of the addition of x kg of lead, the percentage of lead increases while that of tin reduces to 38%. This means that the resultant percentage of lead is 62%, which also means that tin and lead are now in the ratio of 38:62 OR 19:31, respectively.
Therefore,
\(\frac{57 }{ (43 + x)}\) = \(\frac{19 }{ 31}\)
Simplifying and solving the above equation, x = 50.
50 kg of lead should be added to the 100kg mixture to reduce the percentage of tin to 38%.
The correct answer option is C.
