Question: One can use three different transports which move at 10, 20, and 30 kmph, respectively. To reach from A to B, Amal took each mode of transport for 1/3 of his total journey time, while Bimal took each mode of transport for 1/3 of the total distance. The percentage by which Bimal’s travel time exceeds Amal’s travel time is nearest to
Let time taken by Amal be 3t, so time taken with each speed = 3t/3 = t.
Let total distance travelled be 3d. Hence, Bimal travels d at each of the 3 different speeds.
For Amal : 3d = 10t + 20t + 30t = 60t.
∴ d = 20t.
Time taken by Bimal = (d/10) + (d/20) + (d/30) = (11d/60) = 11t/3.
Required percentage = [{(11t/3)/3t} − 1] × 100 = (2/9) × 100 = 22.22 ≈ 22%.
Hence, option (a).