swerve wrote:A certain school teaches fourth, fifth, and sixth grades only, with 150 students in each grade. During one day of a blizzard, 10% of the fourth-grade students, 1/6 of the fifth-grade students, and 60 of the sixth-grade students do not attend school. The student attendance on that day is approximately what percent less than full attendance?

A. 11%
B. 16%
C. 22%
D. 31%
E. 33%

The OA is C

Source: Princeton Review

Given that there are 150 students in each of the fourth, fifth, and sixth grades, the full attendance = 3*150 = 450.

Number of fourth-grade students who do not attend school due to blizzard = 10% of 150 = 15;
Number of fifth-grade students who do not attend school due to blizzard = 1/6 of 150 = 25;
Number of fourth-grade students who do not attend school due to blizzard = 60;

Total number of students who do not attend school due to blizzard = 15 + 25 + 60 = 100

Thus, the student attendance on that day is ~(100/450)*100% = 22 percent less than full attendance

The correct answer: C

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: GMAT Classes Atlanta | GMAT Tutoring Philadelphia | GRE Prep Denver | TOEFL Prep Classes San Jose | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

swerve wrote:A certain school teaches fourth, fifth, and sixth grades only, with 150 students in each grade. During one day of a blizzard, 10% of the fourth-grade students, 1/6 of the fifth-grade students, and 60 of the sixth-grade students do not attend school. The student attendance on that day is approximately what percent less than full attendance?

A. 11%
B. 16%
C. 22%
D. 31%
E. 33%

The OA is C

Source: Princeton Review

Full attendance is 150 x 3 = 450 students.

Because of the blizzard, 0.9 x 150 = 135 fourth graders came to school, (5/6) x 150 = 125 fifth graders came to school, and 150 - 60 = 90 sixth graders came to school. So, 135 + 125 + 90 = 350 students came to school.

Now we can determine what percentage less than full attendance this student attendance is.

(350 - 450)/450 = -100/450 x 100 ≈ -22% = 22% less

Answer: C

swerve wrote:A certain school teaches fourth, fifth, and sixth grades only, with 150 students in each grade. During one day of a blizzard, 10% of the fourth-grade students, 1/6 of the fifth-grade students, and 60 of the sixth-grade students do not attend school. The student attendance on that day is approximately what percent less than full attendance?

A. 11%
B. 16%
C. 22%
D. 31%
E. 33%

The OA is C

Source: Princeton Review

Full attendance is 150 x 3 = 450 students.

Because of the blizzard, 0.9 x 150 = 135 fourth graders came to school, (5/6) x 150 = 125 fifth graders came to school, and 150 - 60 = 90 sixth graders came to school. So, 135 + 125 + 90 = 350 students came to school.

Now we can determine what percentage less than full attendance this student attendance is.

(350 - 450)/450 = -100/450 x 100 ≈ -22% = 22% less

Answer: C