if the length and breadth of a rectangular room are each increased by 1 m , then the area of floor is increased by 21 sq . m . if the length is creased by 1 m and breadth is decreased by 1 m , then the area is decreased by 5 sq . m . the perimeter of the floor is :
n0 = 1.0
n1 = 21.0
n2 = 1.0
n3 = 1.0
n4 = 5.0
t0 = n1 - n4
t1 = n1 - n0
t2 = t0 / 2.0
t3 = t1 - t2
answer = 2 * (t2 + t3)  # perimetere of rectangle
print(answer)