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Bunuel
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 03:58
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E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

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25% (medium)

Question Stats:

72% (01:20) correct 28% (01:19) wrong based on 134 sessions

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In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%
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E
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rajatchopra1994
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 04:02
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let in one class , total student is 100
so with tattos is 60.
In another total student will be 200, & with tattos it will be 40.

So required % = (100/300)x100 = 33.33 %

IMO-B
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In a college lecture hall, 60% of the students have tattoos. In a seco Updated on: 09 Jul 2020, 04:11
Originally posted by v12345 on 09 Jul 2020, 04:05.
Last edited by v12345 on 09 Jul 2020, 04:11, edited 1 time in total.
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Bunuel
In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Let students in first class be 100.
Students with tattoos = 60
Students in second class = 200
Students with tattoos = 40
Total Students with tattoos = 40 + 60 = 100
So students without tattoos = 200
Total Students = 100 + 200 = 300
percent of both classes are students without tattoos = 200/300 * 100% = 66 2/3%
Hence, OA is (E).
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 04:08
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Let,
class 1 = C1 = 100 students
class 2 = C2 = 200 students

For C1:
Students with tattoos = 60
Students without tattoos = 40 ....... (i)

For C2:
Students with tattoos = 40
Students without tattoos = 160 .......(ii)

From (i) and (ii)
Total number of students without tattoos = 200

Ratio = 200/300 = 66.66%

Answer: E
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 04:09
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Bunuel
In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Let students in first class be 100.
Students with tattoos = 60
Students in second class = 200
Students with tattoos = 40
Total Students with tattoos = 40 + 60 = 100
Total Students = 100 + 200 = 300
percent of both classes are students without tattoos = 100/300 * 100% = 33 1/3%
Hence, OA is (B).

Hey! Shouldn't the number of students without tattoos be 40 + 160 = 200 ??
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 04:10
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rajatchopra1994
let in one class , total student is 100
so with tattos is 60.
In another total student will be 200, & with tattos it will be 40.

So required % = (100/300)x100 = 33.33 %

IMO-B

Hey! Shouldn't the number of students without tattoos be 40 + 160 = 200 ??
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 05:18
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Bunuel
In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Let, in the first class total size of student is \(X\);

Thus, students with tattoos = \(0.6X\) and without tattoo = \(X\) - \(0.6X\) = \(0.4X\);

In second class total size of student is \(2X\);

Thus, students with tattoos = \(2X\) x \(0.2\) = \(0.4X\) and without tattoo = \(2X\) - \(0.4X\) = \(1.6X\);

Hence, total students without tattoo = \(0.4X\) + \(1.6X\) = \(2X\)

Required percentage = \(\frac{2X}{3X}\) x 100% = 66\(\frac{2}{3}\)%

IMO ans is E
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 07:11
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Bunuel

In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Is there a mistake in the first line ? 'In a college lecture hall, 60% of the students have tattoos.' Shouldn't it be in the 1st class and not lecture hall ?

Posted from my mobile device
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 07:29
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Bunuel

In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Is there a mistake in the first line ? 'In a college lecture hall, 60% of the students have tattoos.' Shouldn't it be in the 1st class and not lecture hall ?

Posted from my mobile device


Lecture hall means class, think of a university.

In a second class means second lecture hall.
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In a college lecture hall, 60% of the students have tattoos. In a seco 09 Jul 2020, 08:04
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Bunuel

In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Is there a mistake in the first line ? 'In a college lecture hall, 60% of the students have tattoos.' Shouldn't it be in the 1st class and not lecture hall ?

Posted from my mobile device


Lecture hall means class, think of a university.

In a second class means second lecture hall.

Right, thanks for helping me out ! :)
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In a college lecture hall, 60% of the students have tattoos. In a seco 29 Aug 2021, 12:32
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If A =100 then Students having tattoos = 60
Now, B= 200, then Students having tattoos = 40

% Students without tattoos = 1- (60+40)/(100+200) = 2/3*100 = 66.67%

So, I think E. :)
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In a college lecture hall, 60% of the students have tattoos. In a seco 30 May 2022, 06:54
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Bunuel

In a college lecture hall, 60% of the students have tattoos. In a second class that is twice the size of the first, 20% of the students have tattoos. What percent of both classes are students without tattoos?

A. 30%
B. 33 1/3%
C. 40%
D. 50%
E. 66 2/3%

Is there a mistake in the first line ? 'In a college lecture hall, 60% of the students have tattoos.' Shouldn't it be in the 1st class and not lecture hall ?

Posted from my mobile device


Lecture hall means class, think of a university.

In a second class means second lecture hall.
Babineaux Bunuel

How can we assume that college lecture hall means first class? I thought that college lecture hall includes all classes i.e. 1st, 2nd and even later years and so unable to solve the problem.
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