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 less in a row there would be 4 rows more. Find the number of students in the class

Answer 1

no. of students in a row = y
no. of rows = x
so no. of student in class = no. of student in a row*no. of rows = xy
according to question,
(y+4) (x-2)=no. of student=xy
xy - 2y + 4x - 8 = xy
4x - 2y = 8
2x - y = 4------------(1)

(y - 4) (x + 4)= no. of students in class=xy
xy + 4y - 4x - 16 = xy
- x + y = 4-----------(2)
by solving equation (1) & (2)
x=8
y=12
so number of students in class = xy = 12 x 8 = 96.