Laxmi and Prasanna set on a journey. Laxmi moves northwards at a speed of 18 kmph and Prasanna moves southward at a speed of 27 kmph. How far will be Prasanna from Laxmi after 60 minutes ?  Choose the correct choice from the following answers: A) 11 B) 50 C) 28 D) 45 E) 18

Rationale: "explanation : we know 60 min = 1 hr total northward laxmi ' s distance = 18 kmph x 1 hr = 18 km total southward prasanna ' s distance = 27 kmph x 1 hr = 27 km total distance between prasanna and laxmi is = 18 + 27 = 45 km . answer : d"
Answer: D