Sravan travelled for 15 hours. He covered the first half of the distance at 45 kmph and remaining half of the distance at 30 kmph. Find the distance travelled by Sravan?  Answers
A) 520 B) 540 C) 550 D) 560 E) 440

Rationale: let the distance travelled be x km . total time = ( x / 2 ) / 45 + ( x / 2 ) / 30 = 15 = > x / 90 + x / 60 = 15 = > ( 2 x + 3 x ) / 180 = 15 = > x = 540 km answer : b
Answer: B