Question

in a p.t. display 480 students are arrenged in rows and columns. if there are 4 more students in each row than the number of rows, find the number of students in each row?

Answer 1

The number of students in each row

let the no of rows be x .

total no.of students=x×(x+4)

480=x*x+4x

x2+4x-480=0

x2+24x-20x-480=0

x(x+24)-20(x+24)=0

(x+24)(x-20)=0

x=20 or -24 (24 not possible)

no.of student=x+4=20+4=24student

Answer 2

Answer: The number of rows will be 24.

Step-by-step explanation:

Since we have given that

Total number of students = 480

Let the number of columns be 'x'.

Let the number of rows be 'x+4'

According to question, it becomes

$x(x+4)=480\\\\x^2+4x-480=0\\\\x^2+24x-20x-480=0\\\\x(x+24)-20(x+24)=0\\\\(x+24)(x-20)=0\\\\x=-24,20$

Ignoring the negative value.

The number of columns will be  20.

Hence, The number of rows will be 20+4=24.