141213 A car travels \(1 / 3\) of the distance on a straight road with a velocity of \(10 \mathrm{~km} \mathrm{~h}^{-1}\) next \(1 / 3\) of the distance with velocity \(20 \mathrm{~km} \mathrm{~h}^{-1}\) and the last \(1 / 3\) of the distance with velocity \(60 \mathrm{~km} \mathrm{~h}^{-1}\). The average velocity of the car in the whole journey is
141213 A car travels \(1 / 3\) of the distance on a straight road with a velocity of \(10 \mathrm{~km} \mathrm{~h}^{-1}\) next \(1 / 3\) of the distance with velocity \(20 \mathrm{~km} \mathrm{~h}^{-1}\) and the last \(1 / 3\) of the distance with velocity \(60 \mathrm{~km} \mathrm{~h}^{-1}\). The average velocity of the car in the whole journey is
141213 A car travels \(1 / 3\) of the distance on a straight road with a velocity of \(10 \mathrm{~km} \mathrm{~h}^{-1}\) next \(1 / 3\) of the distance with velocity \(20 \mathrm{~km} \mathrm{~h}^{-1}\) and the last \(1 / 3\) of the distance with velocity \(60 \mathrm{~km} \mathrm{~h}^{-1}\). The average velocity of the car in the whole journey is
141213 A car travels \(1 / 3\) of the distance on a straight road with a velocity of \(10 \mathrm{~km} \mathrm{~h}^{-1}\) next \(1 / 3\) of the distance with velocity \(20 \mathrm{~km} \mathrm{~h}^{-1}\) and the last \(1 / 3\) of the distance with velocity \(60 \mathrm{~km} \mathrm{~h}^{-1}\). The average velocity of the car in the whole journey is