Kimberly left home at 11.25 a.m. and drove towards the province. 2 hours later, her grandfather left their home and drove towards the same province at 100 km/h. When the grandfather reached the province at 6.25 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 grandfather started driving = 1.25 p.m.
Duration that Kimberly's grandfather drove from 1.25 p.m. to 6.25 p.m. = 5 h

Distance that Kimberly's grandfather travelled
= 5 x 100
= 500 km

Distance that Kimberly travelled by the time her grandfather reached the city
= 500 - 3
= 497 km

Time that Kimberly took to travel 497 km = 7 h

Kimberly's average speed
= 497 ÷ 7
= 71 km/h

Answer(s): 71 km/h