Min left home at 11.25 a.m. and drove towards the city. 2 hours later, her older sister left their home and drove towards the same city at 93 km/h. When the older sister reached the city at 4.25 p.m., Min had another 5 km to travel. What was Min’s average speed? Express your answer in mixed number.
Time that the Min's older sister started driving = 1.25 p.m.
Duration that Min's older sister drove from 1.25 p.m. to 4.25 p.m. = 3 h

Distance that Min's older sister travelled
= 3 x 93
= 279 km

Distance that Min travelled by the time her older sister reached the city
= 279 - 5
= 274 km

Time that Min took to travel 274 km = 5 h

Min's average speed
= 274 ÷ 5
= 54⁴₅ km/h

Answer(s): 54⁴₅ km/h