Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
256 views
in Linear Equations by (50.7k points)
closed by

The students of a class are made to stand in rows. If 3 students are extra in a row, there would be 1 row less. If 3 students are less in a row there would be 2 rows more. Find the number of students in the class.

1 Answer

+1 vote
by (49.2k points)
selected by
 
Best answer

Let the number of students in a row be ‘a’ and number of rows be ‘b’.

Given,

3 students are extra in a row, there would be 1 row less. If 3 students are less in a row there would be 2 rows more.

Number of students remain constant .

⇒ ab = (a + 3)(b – 1) ab = (a – 3)(b + 2)

So,

ab = ab - a + 3b - 3a - 3b = - 3 ...... (1)

and

ab = ab + 2a - 3b - 62a - 3b = 6 ...... (2)

Subtract 1 from 2 to get,

2a - 3b - (a - 3b) = 6 - (- 3)2a - 3b - a + 3b = 6 + 3a = 9

Put the value of a in 1 to get,

9 - 3b = - 3 - 3b = - 3 - 9 - 3b = - 12b = 4

Solving the above equations we get,

a = 9 and b = 4

Thus, number of students = ab = (9)(4) = 36

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

...