Sarah left home at 11.50 a.m. and drove towards the town. 2 hours later, her cousin left their home and drove towards the same town at 94 km/h. When the cousin reached the town at 4.50 p.m., Sarah had another 6 km to travel. What was Sarah’s average speed? Express your answer in mixed number.
Time that the Sarah's cousin started driving = 1.50 p.m.
Duration that Sarah's cousin drove from 1.50 p.m. to 4.50 p.m. = 3 h

Distance that Sarah's cousin travelled
= 3 x 94
= 282 km

Distance that Sarah travelled by the time her cousin reached the city
= 282 - 6
= 276 km

Time that Sarah took to travel 276 km = 5 h

Sarah's average speed
= 276 ÷ 5
= 55¹₅ km/h

Answer(s): 55¹₅ km/h