Pritishd wrote:
In a certain high school graduating class, 60 percent of the students plan to attend college, and 40 percent of the students have grade point averages (GPAs) of 3.0 or above. If 30 percent of the students who plan to attend college have GPAs of 3.5 or above, how many of the students who plan to attend college have GPAs of 3.5 or above?
(1) 90 of the students who plan to attend college have GPAs of 3.0 or above.
(2) 90 of the students in the graduating class have GPAs of 3.5 or above.
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This is what the question stem gives us. We need to know the value of the shaded region (the cross hatched region).
(1) 90 of the students who plan to attend college have GPAs of 3.0 or above.
This tells us that the shaded region + dotted region = 90.
How much is the shaded region out of it, we do not know. Not sufficient.
(2) 90 of the students in the graduating class have GPAs of 3.5 or above.
30% of T = 90
T = 300
So Students planning to attend college = 60% of T = 60% of 300 = 180
No of students with GPA > 3.0 = 40% of T = 40% of 300 = 120
Don't know the shaded region. Insufficient.
Using both, this is the info we have:
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180 + 120 - 90 = 210 (no of students planning to attend college or with GPA > 3.0)
But we still don't know the value of cross hatched area. Let's try to give it 2 different values to see if all works in both cases.
Say the cross hatched area is 80. Then the dotted region is 10.
Say the cross hatched area is 60. Then the dotted region is 30.
Works in both cases. Not sufficient.
Answer (E)