At a certain university, 3 out of every 5 students live in an on-campus dormitory. If one out of every 10 students who

This topic has expert replies
Legendary Member
Posts: 2276
Joined: Sat Oct 14, 2017 6:10 am
Followed by:3 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

At a certain university, 3 out of every 5 students live in an on-campus dormitory. If one out of every 10 students who do not live in an on-campus dormitory lives in a university-owned apartment, what fractional part of the student body does not live in either an on-campus dormitory or a university-owned apartment?

A. 7/10
B. 1/2
C. 9/25
D. 3/10
E. 7/25

Answer: C

Source: Princeton Review
Source: — Problem Solving |

Legendary Member
Posts: 2214
Joined: Fri Mar 02, 2018 2:22 pm
Followed by:5 members
Students in on-campus dormitory = 3 out of 5 = 3/5
Students that are not in on-campus lives in a university-owned apartment = 1 out of 10 = 1/10
Let total students = x
$$\frac{3}{5}x=on\ campus\ and\ remaining\ student$$
$$=\frac{1x}{1}-\frac{3x}{5}=\frac{5x-3x}{5}=\frac{2x}{5}$$
From the remaining 2x/5, 1/10 students who are not on campus dormitory are in the university-owned apartment.
$$Therefore,\ \frac{1}{10}\cdot\frac{2x}{5}=\frac{1}{25}x\ live\ in\ the\ university-owned\ apartment.$$
Students who do not live on campus and do not live in a university-owned apartment will be;
$$=\frac{2}{5}x-\frac{1}{25}x=\frac{10x-x}{25}=\frac{9x}{25}$$
As a fraction of total, 9/25 of the total students lived in neither on-campus dormitory nor university-owned apartments. Hence, the correct answer is option C.