Question

the student of a class are made to stand in a row ..iff three student are extra in a row ther would be 1;row less ..if three students are less ina row ,there would be two rows more ..find the number of students in the class

hopebu give rigjt answer and will take the reward of brainlist answer.

Answer 1

Let the number of students in each row = x.

Let the number of rows = y.

The total number of students = xy.

Given that if three students are extra in a row would be 1 row less.

Then the total number of students = (x - 1)(y + 3).

xy = (x - 1)(y + 3)

xy = xy + 3x - y - 3

3x - y = 3.   ----- (1)


Given that if three students are less in a row, there would be two rows more.

Then the total number of students = (x + 2)(y - 3)

xy = (x + 2)(y - 3)

xy = xy - 3x + 2y - 6

3x - 2y = -6   -------- (2)


On Solving (1) & (2), we get

3x - 2y = -6

3x - y = 3
--------------------
      -y = -9

       y = 9


Substitute y = 9 in (2), we get

3x - 2(9) = -6

3x - 18 = -6

3x = -6 + 18

3x = 12

x = 4.


Hence the number of rows = 4.

Hence the number of students = 9.

Therefore the number of students in the class = 4 * 9

                                                                             = 36.



Hope this helps!

Answer 2

Hey mate..
========

Let the no. of rows be x

And the no. of students in the row be y.

So,

No. of students in the class = xy

A/Q,

Total no. of students = ( x-1 ) ( y+3)

=> xy = ( x-1 ) ( y+3 )

=> xy = x ( y+3 ) -1 ( y+3 )

=> xy = xy + 3x - y - 3

=> 3x - y - 3 = 0

=> 3x - y = 3.........(1)

Again,

Total no. of students = ( x+2 )( y-3 )

=> xy = x ( y-3 ) + 2 ( y-3 )

=> xy = xy - 3x + 2y -6

=> 3x - 2y = -6.........(2)

Subtracting equation (2) from (1), we obtain:

y = 9

Substituting the value of y in equation (1), we obtain:

=> 3x – 9 = 3

=> 3x = 9 + 3 = 12

=> x = 4

Thus,

Number of rows = x = 4

Number of students in a row = y = 9

So,

Total no. of students in the class , xy

= ( 9×4 )

= 36

Hope it helps !!!