Xandra left home at 10.45 a.m. and drove towards the province. 3 hours later, her mother left their home and drove towards the same province at 81 km/h. When the mother reached the province at 6.45 p.m., Xandra had another 3 km to travel. What was Xandra’s average speed? Express your answer in mixed number.
Time that the Xandra's mother started driving = 1.45 p.m.
Duration that Xandra's mother drove from 1.45 p.m. to 6.45 p.m. = 5 h

Distance that Xandra's mother travelled
= 5 x 81
= 405 km

Distance that Xandra travelled by the time her mother reached the city
= 405 - 3
= 402 km

Time that Xandra took to travel 402 km = 8 h

Xandra's average speed
= 402 ÷ 8
= 50¹₄ km/h

Answer(s): 50¹₄ km/h