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In a certain high school, 20 percent of the students in the sophomore
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09 Oct 2019, 22:03
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81% (01:51) correct 19% (01:55) wrong based on 31 sessions
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Competition Mode Question In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class? A. 66 B. 50 C. 44 D. 36 E. 34
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Re: In a certain high school, 20 percent of the students in the sophomore
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09 Oct 2019, 22:30
10+ (30/100*80) 10+ 24 =34
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Re: In a certain high school, 20 percent of the students in the sophomore
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09 Oct 2019, 23:21
Let total number of Sophomore class be 100. The portion of the class who have Driver's License, A, = 20% = 20 The portion of the class without a Driver's License, B, = 80% = 80
We know from the question stem that half of the class with Driver's License took Driver Education Classes. This implies half of A did not take Driver's Education Class. Hence number out of A, who do not have Driver's Education = 0.5*20 = 10
We also know from the question stem that 70% of those without Driver's License, B, took Driver Education Classes, implying 30% of B did not take the class. Number out of A without the class = 0.3*80 = 24 Total without the class = 24+10 = 34 Hence 34% did not take the Driver Education Class.
Option E is the answer in my view.



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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 01:07
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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 03:02
In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class?
assume there are 100 sophomore 20% of sophomore have driver's license: 20 half of those took driver's class: 10 of sophomore w/o license, 70% taken driver's class: .7x(10020): 56 what percentage of the class(sophomore) has not taken a driver's class: 1001056=34
Therefore, E



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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 03:27
In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class? A. 66 B. 50 C. 44 D. 36 E. 34 Half of students with drier's license have taken driver's education class i.e 20%/2 = 10% Since 80% students are without a license which includes 70% who have taken driver's education class and remaining without it, percentage of students without driver's education class is 30% * 80% = 24% Hence total students without driver's education class = 24 + 10 = 34% IMO Answer E.
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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 05:18
Quote: In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class?
A. 66 B. 50 C. 44 D. 36 E. 34 ............drivers:......not: class…..0.5(1/5)....0.7(4/5) not…....0.5(1/5)......0.3(4/5) total.......1/5........4/5 not: 0.5(1/5)+0.3(4/5)=34/100 Answer (E)



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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 06:23
solve using 2x2 matrix DLNDLTotal Class105666 nclas102434 total2080100
IMO E; 34
In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class?
A. 66 B. 50 C. 44 D. 36 E. 34



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Re: In a certain high school, 20 percent of the students in the sophomore
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10 Oct 2019, 13:16
Let 100 be the number of students in the sophomore class. —> 20% of them have a driver’s license: —> 10 of them took driver’s education class —> the other 10 students didn’t take driver’s education class
80 students don’t have driver’s license: —> 80*70%= 80*70/100=56 students have taken the driver’s education class. —> 80– 56= 24 students haven’t taken that class. In total, there are 10+24=34 students have not taken the driver’s education class —> that means 34 % of the class have not taken the driver’s education class.
The answer is E
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Re: In a certain high school, 20 percent of the students in the sophomore
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13 Oct 2019, 18:27
Bunuel wrote: Competition Mode Question In a certain high school, 20 percent of the students in the sophomore class have obtained a driver's license, and half of those students took a driver's education class. Of the sophomores without a license, 70 percent have taken a driver's education class. What percentage of the class has not taken a driver's education class? A. 66 B. 50 C. 44 D. 36 E. 34 We can let n = the total number of students in the sophomore class. We know that 0.2n have a license and 0.8n do not have a license. 0.2n * 0.5 = 0.1n took a driver’s education class and have a licence and 0.8n * 0.7 = 0.56n took a driver’s education class but do not have a licence. Thus, 0.1n + 0.56n = 0.66n students took a driver’s education class, which means 0.34n, or 34% of the students, have not taken a driver’s education class. Answer: E
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Re: In a certain high school, 20 percent of the students in the sophomore
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