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smclean23
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PostPosted: Sun Jul 06, 2008 2:05 pm    Post subject: Simple.....got the answer right, but by guess-estimating... Reply with quote

Of a certain high school graduating class, 75 percent of the students continued their formal education, and 80 percent of those who continued their formal education went to four-year colleges. If 300 students in the class went to four-year colleges, how many students were in the graduating class?
(A) 500
(B) 375
(C) 240
(D) 225
(E) 180
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PostPosted: Sun Jul 06, 2008 3:45 pm    Post subject: Reply with quote

Of a certain high school graduating class, 75 percent of the students continued their formal education, and 80 percent of those who continued their formal education went to four-year colleges. If 300 students in the class went to four-year colleges, how many students were in the graduating class?

Given Data:

80 percentage makes 300

then 100 percentage makes 375 ==> which is 75 percentage who continued formal education

then 100 percentage makes 500

the no of students in the graduating class is 500

A is the answer
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PostPosted: Wed Jul 09, 2008 4:10 am    Post subject: Re: Simple.....got the answer right, but by guess-estimating Reply with quote

To Find => no. of students n the graduating class = say, x

Given that - "75 percent of the students continued their formal education"
i.e. (75/100)*x continued formal education.

So no. of students taking formal ed. = (3/4)*x

also given that - "80 percent of those who continued their formal education went to four-year colleges" And that number happens to be 300 acc to the question

therefore 0.8*(3/4)*x = 300

Solve for x.

x=500

HTH

Amit
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PostPosted: Wed Jul 09, 2008 9:37 am    Post subject: Reply with quote

For some reason I couldn't get an answer, even though I am usually pretty good at this problem type.

I divided the students into four groups:

1 - Those with formal education and four year college

2 - Those with formal education but no four year college

3 - Those with no formal education and a four year college

4 - Those with neither

When I attempted this problem using this method, I ended up with .6x for Group 1 and a total of 300 for those with a four year college, but was left with unknown for Group 3. Now, from this setup one could say that Group 3 is then .4x, but that makes no sense.

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