Emily left home at 11.30 a.m. and drove towards the campsite. 3 hours later, her auntie left their home and drove towards the same campsite at 82 km/h. When the auntie reached the campsite at 7.30 p.m., Emily had another 2 km to travel. What was Emily’s average speed? Express your answer in mixed number.
Time that the Emily's auntie started driving = 2.30 p.m.
Duration that Emily's auntie drove from 2.30 p.m. to 7.30 p.m. = 5 h

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

Distance that Emily travelled by the time her auntie reached the city
= 410 - 2
= 408 km

Time that Emily took to travel 408 km = 8 h

Emily's average speed
= 408 ÷ 8
= 51 km/h

Answer(s): 51 km/h