Kimberly left home at 11.45 a.m. and drove towards the campsite. 2 hours later, her auntie left their home and drove towards the same campsite at 86 km/h. When the auntie reached the campsite at 6.45 p.m., Kimberly had another 3 km to travel. What was Kimberly’s average speed? Express your answer in mixed number.
Time that the Kimberly's auntie started driving = 1.45 p.m.
Duration that Kimberly's auntie drove from 1.45 p.m. to 6.45 p.m. = 5 h

Distance that Kimberly's auntie travelled
= 5 x 86
= 430 km

Distance that Kimberly travelled by the time her auntie reached the city
= 430 - 3
= 427 km

Time that Kimberly took to travel 427 km = 7 h

Kimberly's average speed
= 427 ÷ 7
= 61 km/h

Answer(s): 61 km/h