Nicole left home at 11.25 a.m. and drove towards the city. 2 hours later, her grandfather left their home and drove towards the same city at 88 km/h. When the grandfather reached the city at 5.25 p.m., Nicole had another 4 km to travel. What was Nicole’s average speed? Express your answer in mixed number.
Time that the Nicole's grandfather started driving = 1.25 p.m.
Duration that Nicole's grandfather drove from 1.25 p.m. to 5.25 p.m. = 4 h

Distance that Nicole's grandfather travelled
= 4 x 88
= 352 km

Distance that Nicole travelled by the time her grandfather reached the city
= 352 - 4
= 348 km

Time that Nicole took to travel 348 km = 6 h

Nicole's average speed
= 348 ÷ 6
= 58 km/h

Answer(s): 58 km/h