Marion left home at 11.15 a.m. and drove towards the seaside resort. 2 hours later, her older sister left their home and drove towards the same seaside resort at 94 km/h. When the older sister reached the seaside resort at 4.15 p.m., Marion had another 2 km to travel. What was Marion’s average speed? Express your answer in mixed number.
Time that the Marion's older sister started driving = 1.15 p.m.
Duration that Marion's older sister drove from 1.15 p.m. to 4.15 p.m. = 3 h

Distance that Marion's older sister travelled
= 3 x 94
= 282 km

Distance that Marion travelled by the time her older sister reached the city
= 282 - 2
= 280 km

Time that Marion took to travel 280 km = 5 h

Marion's average speed
= 280 ÷ 5
= 56 km/h

Answer(s): 56 km/h