There are 20 students in a class. they sit in pairs so that exactly one third of the boys sit with a girl, and exactly one half of the girls sit with a boy. total how many boys are there in the class?
i am not sure how to work this question out algebraically. can i have some help please?
Answers
Step-by-step explanation:
GMAT Club
FORUM
GMAT CLUB TESTS
QUESTION BANKS
DECISION TRACKER
SCHOOL DISCUSSIONS
REVIEWS
DEALS & DISCOUNTS
CHAT
T&C AND PRIVACY POLICY
GMAT Club Rules
Login
Username
Password
Register Forgot password?
Close
Search
Close
GMAT Club Forum Index Data Sufficiency (DS)
There were n boys and m girls in a class. : Data Sufficiency (DS)
TAGS
DarshilPandya
Jun 18, 2018
00:00ABCDE
DIFFICULTY: 65% (hard) QUESTION STATS: based on 173 sessions
53% (01:36) correct
47% (01:46) wrong
There were n boys and m girls in a class. They wanted to sit in a row for an activity. In how many ways can they sit on 30 chairs?
I. n+3m = 20
II. 2n + 2m = 22
Spoiler: OA
Kudos
0 kudos, 7 bookmarks
GMATBusters
EXPERT'S
POST
Jun 18, 2018
There were n boys and m girls in a class. They wanted to sit in a row for an activity. In how many ways can they sit on 30 chairs?
To find the number of ways , we need the total number of students.
If N is total number of students, Number of ways will be
I. n+3m = 20
Value of (n, m) can be (2,6) or (5,5) or (8,4)
So N = n+m= 8 or 10 or 12.
NOT SUFFICIENT.
II. 2n + 2m = 22
N= n+m = 11
SUFFICIENT.
Answer B
_________________
GMATBusters Quant Quizzes are back with a BANG- Win Prizes worth more than 500$
Book online tutoring session