Nicole left home at 11.10 a.m. and drove towards the town. 2 hours later, her grandfather left their home and drove towards the same town at 86 km/h. When the grandfather reached the town at 4.10 p.m., Nicole had another 5 km to travel. What was Nicole’s average speed? Express your answer in mixed number.
Time that the Nicole's grandfather started driving = 1.10 p.m.
Duration that Nicole's grandfather drove from 1.10 p.m. to 4.10 p.m. = 3 h

Distance that Nicole's grandfather travelled
= 3 x 86
= 258 km

Distance that Nicole travelled by the time her grandfather reached the city
= 258 - 5
= 253 km

Time that Nicole took to travel 253 km = 5 h

Nicole's average speed
= 253 ÷ 5
= 50³₅ km/h

Answer(s): 50³₅ km/h