The area of a square field is 1225 km2. How long will it take for a horse to run around at the speed of 20 km/h ?  Pick one
A) 7 h	B) 10 h	C) 8 h	D) 6 h	E) none of these

Rationale: explanation area of field = 1225 km 2 . then , each side of field = √ 1225 = 35 km distance covered by the horse = perimeter of square field = 35 × 4 = 140 km ∴ time taken by horse = distances / peed = 140 / 20 = 7 h answer a
Answer: A