Fiona left home at 10.55 a.m. and drove towards the suburb. 3 hours later, her mother left their home and drove towards the same suburb at 92 km/h. When the mother reached the suburb at 6.55 p.m., Fiona had another 6 km to travel. What was Fiona’s average speed? Express your answer in mixed number.
Time that the Fiona's mother started driving = 1.55 p.m.
Duration that Fiona's mother drove from 1.55 p.m. to 6.55 p.m. = 5 h

Distance that Fiona's mother travelled
= 5 x 92
= 460 km

Distance that Fiona travelled by the time her mother reached the city
= 460 - 6
= 454 km

Time that Fiona took to travel 454 km = 8 h

Fiona's average speed
= 454 ÷ 8
= 56³₄ km/h

Answer(s): 56³₄ km/h