Question

Students of a class are made to stand in rows .if 4students are extra in a row ,their would be 2rows less.if 4students are less in a row ,there would be 4more rows .find the numbers of students

Answer 1

Answer:

96

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)

Adding (i)  and (ii)

2x=24 ⟹x=12

Substitute value of x in either  (i)  or  (ii) to calculate y .

Putting in  (i)  , -2 * 12 + 4y = 8 => 4y = 32  => y = 8.

So, the number of students =  xy = 12×8 = 96