The students of a class are made to stand in rows. If 4 students are extra in
each row, there would be 2 rows less. If 4 students are less in each row, there
would be 4 more rows. What is the number of students in the class?
Answers
Answer:
please mark me brainlest
Step-by-step explanation:
Let the number of students in each row =x & the number of rows =y.
So, the number of students =xy.
Then, by the first condition,
(x+4)(y−2)=xy
⟹−2x+4y−8+xy=xy
⟹−2x+4y=8 .......(i)
Also by the second condition,
(x−4)(y+4)=xy
⟹4x−4y−16+xy=xy
⟹4x−4y=16 .......(ii)
(i)+(ii)⟶2x=24
⟹x=12
∴y=
4
2x+8
=
2
x+4
=
2
12+4
=8
So, the number of students is xy=12×8=96
Answer ByavatarToppr
SHARE
ASK
Get Instant Solutions, 24x7
No Signup required
girl
Prev Question
Next Question
Practice important Questions
IIT Foundation Class 8 Mathematics Chapter 9 to 14
238 Qs
Related Questions to study
If 3x+5y=9 and 5x+3y=7, then what is the value of x+y?
Study later
View Answer
A and B are points 150 km apart or a highway two cars start with different speeds from A and B at same time. if they move in same direction, they meet in 15 hours and if they move in opposite direction they meet in one hour. Find they speeds.
Study later
View Answer
VIEW MORE
Revise with Concepts
Miscellaneous Problems using Simultaneous Equations
EXAMPLE
DEFINITIONS
FORMULAES
20,000+
Learning videos
8,000+
Fun stories
10,000+
Fundamental concepts
8,00,000+
Homework Questions
BROWSE BY
ClassesBoardsExams
MODULES
Online ClassesMock TestsAdaptive PracticeLive Doubts
Stay upto date with our Newsletter!
Stay informed, stay ahead. Be a topper
Your email address
About Us
Brand Resources
Press
Customer Stories
Jobs
Educators
Fellowship
Learning Planet
Guides
Ask
Blog
Bytes
News
Terms of Service
Privacy Policy
Contact Us
FAQs
Google Play
App Store
Answer:
96 students
Step-by-step explanation:
let no of rows = x
let no of students in each row = y
total no of students = xy
⇒ If 4 students are extra in each row, there would be 2 rows less
(y + 4) ( x - 2) = xy
xy - 2y + 4x - 8 = xy
4x - 2y - 8 = 0
2(2x - y - 4) = 0
2x - y - 4= 0
y = 2x - 4 ------{i}
⇒ If 4 students are less in each row, there would be 4 more rows.
(y - 4) (x + 4) = xy
xy + 4y - 4x - 16 = xy
-(-4y + 4x + 4) = 0
4(-y + x + 4) = 0
-y + x + 4 = 0 ------{ii}
from {i} and {ii}
-(2x - 4) + x + 4 = 0
-2x + 4 + x + 4 = 0
x - 8 = 0
x = 8
y = 2x - 4
y = 16 - 4
y = 12
total no of students = xy = 8×12 = 96 students