Nora left home at 11.50 a.m. and drove towards the province. 3 hours later, her auntie left their home and drove towards the same province at 83 km/h. When the auntie reached the province at 7.50 p.m., Nora had another 3 km to travel. What was Nora’s average speed? Express your answer in mixed number.
Time that the Nora's auntie started driving = 2.50 p.m.
Duration that Nora's auntie drove from 2.50 p.m. to 7.50 p.m. = 5 h

Distance that Nora's auntie travelled
= 5 x 83
= 415 km

Distance that Nora travelled by the time her auntie reached the city
= 415 - 3
= 412 km

Time that Nora took to travel 412 km = 8 h

Nora's average speed
= 412 ÷ 8
= 51¹₂ km/h

Answer(s): 51¹₂ km/h