Question

The students of a class are made to stand in rows. If 4 students are extra in a row, there would be 2 rows less. If 4 students are less in a row, there would be 4 rows more. Find the number of students in the class.

Updated on May 31, 2025 | By Learnzy Admin | 👁️ Views: 384 students

Solution
✔ Verified

Let the number of students in each row be x and the number of rows be y.
So, the total number of students is x × y.

First condition:
If 4 students are added to each row, the number of rows becomes 2 less.

This gives the equation:
(x + 4)(y - 2) = x × y
 =>   xy - 2x + 4y - 8 = xy
=>    -2x + 4y = 8    ------------------------------------ (1)

Second condition:
If 4 students are removed from each row, the number of rows becomes 4 more.

This gives the equation:
(x - 4)(y + 4) = x × y
=>   xy + 4x - 4y - 16 = xy
=>   4x - 4y = 16     ---------------------------------- (2)

Now add both equations:

(−2x + 4x) + (4y − 4y) = 8 + 16
=>  2x = 24  =>  x = 12

Now put x = 12 into Equation 1:

−2(12) + 4y = 8
=>   −24 + 4y = 8
=>   4y = 32   =>    y = 8

Hence  Students in each row = 12 & Number of rows = 8

Total students = 12 × 8 = 96

So, there are 96 students in the class.

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