Emma left home at 10.25 a.m. and drove towards the countryside. 3 hours later, her auntie left their home and drove towards the same countryside at 82 km/h. When the auntie reached the countryside at 6.25 p.m., Emma had another 4 km to travel. What was Emma’s average speed? Express your answer in mixed number.
Time that the Emma's auntie started driving = 1.25 p.m.
Duration that Emma's auntie drove from 1.25 p.m. to 6.25 p.m. = 5 h

Distance that Emma's auntie travelled
= 5 x 82
= 410 km

Distance that Emma travelled by the time her auntie reached the city
= 410 - 4
= 406 km

Time that Emma took to travel 406 km = 8 h

Emma's average speed
= 406 ÷ 8
= 50³₄ km/h

Answer(s): 50³₄ km/h