Ivory left home at 10.45 a.m. and drove towards the province. 3 hours later, her uncle left their home and drove towards the same province at 100 km/h. When the uncle reached the province at 6.45 p.m., Ivory had another 6 km to travel. What was Ivory’s average speed? Express your answer in mixed number.
Time that the Ivory's uncle started driving = 1.45 p.m.
Duration that Ivory's uncle drove from 1.45 p.m. to 6.45 p.m. = 5 h

Distance that Ivory's uncle travelled
= 5 x 100
= 500 km

Distance that Ivory travelled by the time her uncle reached the city
= 500 - 6
= 494 km

Time that Ivory took to travel 494 km = 8 h

Ivory's average speed
= 494 ÷ 8
= 61³₄ km/h

Answer(s): 61³₄ km/h