Fiona left home at 11.10 a.m. and drove towards the province. 3 hours later, her father left their home and drove towards the same province at 85 km/h. When the father reached the province at 7.10 p.m., Fiona had another 5 km to travel. What was Fiona’s average speed? Express your answer in mixed number.
Time that the Fiona's father started driving = 2.10 p.m.
Duration that Fiona's father drove from 2.10 p.m. to 7.10 p.m. = 5 h

Distance that Fiona's father travelled
= 5 x 85
= 425 km

Distance that Fiona travelled by the time her father reached the city
= 425 - 5
= 420 km

Time that Fiona took to travel 420 km = 8 h

Fiona's average speed
= 420 ÷ 8
= 52¹₂ km/h

Answer(s): 52¹₂ km/h