    Sentence 1: A man covers 1/3rd of journey by cycle at 50 Km/h,  the néxt 1/3 by car at 30.km/h, rest walking at 7 km/h. average  speed dhiring the whole jourriey.?    Sentence 2: If a person covers 1/3rd of his joutmey by cycle at 50,  the next: 1/3¢d by car at 30 kinph and the rest by walking at 7 km/|  bh, what i his average speed during the whole journey?    