Question

student in a class are made to stand in rows if 2 studen ts are more in a row the no of row decreases by 1 however if 3 students are less in a row increases by 2 .find the number of students in the class

Answer 1

Let the number of rows be x

Number of students in 1 row = y

According to the question,

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

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

(y - 3) (x + 2) = xy  xy - 3x + 2y - 6 = xy

Or -3x + 2y = 6 ...(2)

Adding (1) and (2), we get,

y = 9

3x - 9 = 3  x = 4

Number of students = xy = 4  9 = 36