A rectangular plot measuring 40 meters by 50 meters is to be enclosed by wire fencing. If the poles of the fence are kept 5 meters apart. How many poles will be needed? Choose the correct answer:
A) 46 m	B) 36 m	C) 26 m	D) 56 m	E) 25 m

Rationale: "perimeter of the plot = 2 ( 40 + 50 ) = 180 m no of poles = 180 / 5 = 36 m answer : b"
Answer: B