Let's solve it using 2x2 Matrix
Refer Attached Image
Now it is given to us that
"This year, 15% of the students who received a final grade in Professor Smith's American History class received a grade higher than a 8"=> Value under This year and "Grade > 8" is 15% of the total value under this year. Let total Value under this year be 100.
=> Value under This year and "Grade > 8" is 15% = 15% of 100 = 0.15* 100 = 15
"half the number of students who received a grade higher than a 8 last year"=> Last Year students with "Grade > 8" were Twice what we have this year
=> Value under Last Year and "Grade > 8" = 2 * This Year and "Grade > 8" = 2 * 15 = 30
Now we need to
"the number of students who received a grade of a 8 or below this year" to find the final answer.
Now we know that total grades this year = 100 and this year and grade > 8 = 15
=> This year Grades <= 8 = 100 - 15 = 85
The number of students who received a grade higher than 8 last year is approximately what percent of the number of students who received a grade of a 8 or below this year =\( \frac{30}{85}\) * 100 ~ 35 %
So , Answer will be B
Hope it helps!
Attachments

Image.jpg [ 23.5 KiB | Viewed 3357 times ]