For a class of 50 students, the table above reports the number of stud

Question

https://gmatclub.com/forum/download/file.php?id=52921 For a class of 50 students, the table above reports the number of students who expected to receive an A, a B, or a C or below as well as the actual number of students who received each grade. How many students who expected to receive a C or below received a grade of C or below? (1) Of the students who expected to receive an A or a B, 80% actually did receive an A or a B. (2) Of the students who expected to receive a B, 6 students actually received a C or below. Annotation 2020-02-12 124747.png

rajatchopra1994 · Answer

Explanation:

Statement 1: 80 % actually recieved A or B.
So, expected Grades of A+B = 25 +15 = 40
Out of 40, 80% recieved grade: 40x0.8 = 32. 
Total students: 50
receive a C or below: 50-32 =18
Sufficient.

Statement 2: 
the students who expected to receive a B, 6 students actually received a C or below: means out of 15, 6 received below C or C
So, B=9 
But we dont know anything about A.

So IMO-A

Kinshook · Answer

Given: For a class of 50 students, the table above reports the number of students who expected to receive an A, a B, or a C or below as well as the actual number of students who received each grade.

Asked: How many students who expected to receive a C or below received a grade of C or below?

(1) Of the students who expected to receive an A or a B, 80% actually did receive an A or a B.
Students expected to receive an A or a B = 25 + 15 = 40
80% 0f 40 = 32 students actually received an A or a B.
Rest 8 students received a C.
Total students receiving a C = 14 
Number of students who are expected to receive a C or below received a grade of C or below = 14 - 8 = 6
SUFFICIENT

(2) Of the students who expected to receive a B, 6 students actually received a C or below.
Since it is not known how many students expected to receive an A received C or below
NOT SUFFICIENT

IMO A

globaldesi · Answer

stmt 1
total expected were 25+15 and 
80% got a or B thus 4/5 *40 = 32 got A or B
actual getting A or B = 18 +18 = 36
thus at least 32 got and 4 did not get that indicates these 4 would be who were expected to get C but got A or B
thus 6 would have got C or below
hence sufficient.

(2) Of the students who expected to receive a B, 6 students actually received a C or below.
this gives no info as only value of expected B is given
this tell out of 14 .. 6 are from B but no clue about rest
hence insufficient
Thus answer is A

1616 · Answer

What was the point of giving actual grade in the table?

Bunuel · Answer

The actual grades help to calculate how many students who expected to receive a C or below actually received a grade of C or below. Check the red parts below:

From (1), since 80% of students expecting an A or B actually received an A or B, then the remaining 20% received a C or below. Thus, 0.2(25 + 15) = 8 students, expecting an A or B, received a C or below. Since  14 students actually received a C or below , and 8 of them were expecting to receive an A or B, the remaining  14 - 8 = 6  were those who expected to receive a C or below and actually did receive a grade of C or below.

For a class of 50 students, the table above reports the number of stud

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For a class of 50 students, the table above reports the number of stud

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