A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.
Choices:  A) 220  B) 222  C) 223  D) 224  E) 225
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   224istance covered in the the first half = 21x   224istance covered in the the second half = 24(10 - x)   But distance covered in the the first half = 224istance covered in the the second half   =&gt; 21x = 24(10 - x)   =&gt; 21x = 240 - 24x   =&gt; 45x = 240   =&gt; 9x = 48   =&gt; 3x = 16   ⇒x=16/3   Hence 224istance covered in the the first half = 21x=21×16/3=7×16=112 km   Total distance = 2×112=224 km   Answer is 224.
<result>D</result>
A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.