If one person completes a journey in 10 hrs. He travels 1st half of the journey at the rate of 21 km/hr and 2nd half at therate of 24 km/hr. Find the total journey in km.  Options.
A) 200 km B) 212 km C) 224 km D) 230 km E) 256 km

Rationale: distance = speed x time let time taken to travel the first half = x hr then time taken to travel the second half = ( 10 - x ) hr distance covered in the the first half = 21 x distance covered in the the second half = 24 ( 10 - x ) but distance covered in the the first half = distance covered in the the second half = > 21 x = 24 ( 10 - x ) = > 21 x = 240 - 24 x = > 45 x = 240 = > 9 x = 48 = > 3 x = 16 ⇒ x = 163 hence distance covered in the the first half = 21 x = 21 × 163 = 7 × 16 = 112 kmtotal distance = 2 × 112 = 224 km c
Answer: C