Sarah left home at 11.30 a.m. and drove towards the town. 2 hours later, her mother left their home and drove towards the same town at 96 km/h. When the mother reached the town at 5.30 p.m., Sarah had another 3 km to travel. What was Sarah’s average speed? Express your answer in mixed number.
Time that the Sarah's mother started driving = 1.30 p.m.
Duration that Sarah's mother drove from 1.30 p.m. to 5.30 p.m. = 4 h

Distance that Sarah's mother travelled
= 4 x 96
= 384 km

Distance that Sarah travelled by the time her mother reached the city
= 384 - 3
= 381 km

Time that Sarah took to travel 381 km = 6 h

Sarah's average speed
= 381 ÷ 6
= 63¹₂ km/h

Answer(s): 63¹₂ km/h