Xuan left home at 11.30 a.m. and drove towards the countryside. 3 hours later, her mother left their home and drove towards the same countryside at 95 km/h. When the mother reached the countryside at 6.30 p.m., Xuan had another 2 km to travel. What was Xuan’s average speed? Express your answer in mixed number.
Time that the Xuan's mother started driving = 2.30 p.m.
Duration that Xuan's mother drove from 2.30 p.m. to 6.30 p.m. = 4 h

Distance that Xuan's mother travelled
= 4 x 95
= 380 km

Distance that Xuan travelled by the time her mother reached the city
= 380 - 2
= 378 km

Time that Xuan took to travel 378 km = 7 h

Xuan's average speed
= 378 ÷ 7
= 54 km/h

Answer(s): 54 km/h