Of a certain high school graduating class, 75 percent of the students

Question

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

Show Answer

Official Answer

A

(A) 500
(B) 375
(C) 240
(D) 225
(E) 180

Skywalker18 · Accepted Answer

Let number of students in graduating class =s
Percentage of students who continued formal education = 75%
Number of students who continued formal education = (75/100)*s
And 80 % of those who continued their formal education went to four year colleges.
Number of students went to four year colleges= (80/100)*(75/100) *s = (3/5)s

(3/5)s = 300
=> s = 500

Answer A

Kurtosis · Answer

If 100 is the number of students in graduating class, (3/4)*(4/5)*100 = 60 is the number of students who went to 4 year colleges.

But, number of students who went to 4 yr colleges = 60*5. Hence number of students in graduating class = 100*5 = 500.

Answer: A

EMPOWERgmatRichC · Answer

Hi All,

This question can be solved by TESTing THE ANSWERS.

It's worth noting that the prompt talks about various percentages of students who continue their educations in certain ways, then tells us that 300 students went on to 4-year colleges. This means that there were MORE than 300 students to start off with. Thus, the correct answer MUST be either A or B.

Since A is a 'nice, round' number, let's TEST that one first.

IF...
Total students = 500
75% continued their formal eduction = (3/4)(500) = 375
Of those, 80% went to 4-year colleges = (4/5)(375) = 300

This is an exact MATCH for what we were told, so this MUST be the answer.

Final Answer:  A

GMAT assassins aren't born, they're made,
Rich

MGMAT780 · Answer

Hi All,
can you please explain the question in detial,
as it asks for If 300 students in the class went to four-year colleges, how many students were in the graduating class?
then how can the answer be A)500?

EMPOWERgmatRichC · Answer

Hi MGMAT780, There are already several explanations in this thread about how to approach this question. Is there some aspect of the prompt that you are having trouble understanding? GMAT assassins aren't born, they're made, Rich Contact Rich at: Rich.C@empowergmat.com www.empowergmat.com

MGMAT780 · Answer

If 300 students in the class went to four-year colleges, how many students were in the graduating class?
am confused with this line, it tells that 300 went to college but the answer is 500

EMPOWERgmatRichC · Answer

Hi MGMAT780, The prompt starts off with an unknown number of students in the HIGH-SCHOOL graduating class. From this group, we're told that 75% continued their education - and then from that "group that continued their education", 80% went to a 4-year college. Thus, that large, unknown number at the beginning is getting smaller and smaller (since less than 100% is moving on with each 'step') and eventually equals 300. Algebraically, that would be... (X)(.75)(.8) = 300 where X is the number of students in the high-school graduating class. From here, you can solve for X and answer the question. GMAT assassins aren't born, they're made, Rich Contact Rich at: Rich.C@empowergmat.com www.empowergmat.com

jameswill8520 · Answer

Answer: (A) 500

Since 75% of the class continued their education and 80% of them went to four-year colleges, that means 60% of the total class went to four-year colleges. If 300 students represent 60%, the total class size is 300 ÷ 0.6 = 500.

Of a certain high school graduating class, 75 percent of the students

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Of a certain high school graduating class, 75 percent of the students

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