Xylia left home at 11.25 a.m. and drove towards the province. 2 hours later, her mother left their home and drove towards the same province at 85 km/h. When the mother reached the province at 5.25 p.m., Xylia had another 4 km to travel. What was Xylia’s average speed? Express your answer in mixed number.
Time that the Xylia's mother started driving = 1.25 p.m.
Duration that Xylia's mother drove from 1.25 p.m. to 5.25 p.m. = 4 h

Distance that Xylia's mother travelled
= 4 x 85
= 340 km

Distance that Xylia travelled by the time her mother reached the city
= 340 - 4
= 336 km

Time that Xylia took to travel 336 km = 6 h

Xylia's average speed
= 336 ÷ 6
= 56 km/h

Answer(s): 56 km/h