Rectangular classroom seats 72 students. If the seats were rearragned with 3 more seats rows in each row, the classroom would have 2 fewer rows.

Find the original number in each row?

[Hint: Let the original number of seats in a row be "X".]

Let the original number of seats in a row be x;

Let the number rows be y;

(x + 3) * (y - 2) = 72 and x * y = 72 = > 72 + 3 * y - 2 * x = 72 = > 3 * y = 2 * x;

=> x is divisible by 3;

1. x = 3 = > y = 72 / 3 = > y = 24;

2. x = 6 = > y = 72 / 6 = > y = 12;

3. x = 9 = > y = 72 / 9 = > y = 8;

4. x = 12 = > y = 72 / 12 =. y = 6;

5. x = 24 =. y = 72 / 24 = > y = 3;

6. x = 36 = > y = 72 / 36 = > y = 2;

7. x = 72 = > y = 72 / 72 = > y = 1;

My analysis tell me that the right answer is 9 seats in a row and 8 rows;

The original number in each row is 9.