Roshel left home at 10.45 a.m. and drove towards the province. 3 hours later, her older sister left their home and drove towards the same province at 97 km/h. When the older sister reached the province at 5.45 p.m., Roshel had another 3 km to travel. What was Roshel’s average speed? Express your answer in mixed number.
Time that the Roshel's older sister started driving = 1.45 p.m.
Duration that Roshel's older sister drove from 1.45 p.m. to 5.45 p.m. = 4 h

Distance that Roshel's older sister travelled
= 4 x 97
= 388 km

Distance that Roshel travelled by the time her older sister reached the city
= 388 - 3
= 385 km

Time that Roshel took to travel 385 km = 7 h

Roshel's average speed
= 385 ÷ 7
= 55 km/h

Answer(s): 55 km/h