GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
At a certain elementary school, 10 percent of the fifth-gra
[#permalink]
18 Dec 2017, 12:45
18 Dec 2017, 12:45
Expert Reply
2
Bookmarks
00:00
Question Stats:
84% (02:29) correct
15% (02:36) wrong based on 19 sessions
Hide Show timer Statistics
At a certain elementary school, 10 percent of the fifth-grade students are members of the school band. If 12 percent of the fifth-grade boys and 8 percent of the fifth-grade girls are members of the band, what percent of the fifth-grade students at the school are boys?
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
Re: At a certain elementary school, 10 percent of the fifth-gra
[#permalink]
20 Dec 2017, 02:04
20 Dec 2017, 02:04
1
Carcass wrote:
At a certain elementary school, 10 percent of the fifth-grade students are members of the school band. If 12 percent of the fifth-grade boys and 8 percent of the fifth-grade girls are members of the band, what percent of the fifth-grade students at the school are boys?
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
Here let boys = b and girls = g
and total students = 100
i.e. b + g =100 --------- equ 1
10% of the students are member of school band = 10% of 100 = 10 students.
out of which 12% are boys and 8% are girls
i.e. 0.12b + 0.08g = 10 ----------equ 2
Now multiplying equation 1 by 0.12,
0.12b + 0.12g =12 ---------equ 3
equ 2 - equ 3
0.04g = 2
or g = 50
Hence b= 50 (from equation 1)
Therefore there are 50% fifth-grade students at the school are boys. option E
Target Test Prep Representative
Joined: 09 May 2016
Status:Head GRE Instructor
Affiliations: Target Test Prep
Posts: 183
Given Kudos: 114
Location: United States
Re: At a certain elementary school, 10 percent of the fifth-gra
[#permalink]
29 May 2018, 06:53
29 May 2018, 06:53
1
Expert Reply
Carcass wrote:
At a certain elementary school, 10 percent of the fifth-grade students are members of the school band. If 12 percent of the fifth-grade boys and 8 percent of the fifth-grade girls are members of the band, what percent of the fifth-grade students at the school are boys?
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
A. 10%
B. 12%
C. 20%
D. 30%
E. 50%
We can let the total number of 5th grade students be 1000.
So 100 5th graders are in the band.
Now let b = the number of boys in 5th grade of the school, so 1000 - b = the number of girls in 5th grade. We can create the equation:
0.12b + 0.08(1000 - b) = 100
0.12b + 80 - 0.08b = 100
0.04b = 20
b = 20/0.04 = 2000/4 = 500
So the number of boys in 5th grade is 500/1000 = 1/2 = 50% of all 5th graders at the school.
Answer: E
