Yoko left home at 11.35 a.m. and drove towards the campsite. 3 hours later, her father left their home and drove towards the same campsite at 88 km/h. When the father reached the campsite at 7.35 p.m., Yoko had another 6 km to travel. What was Yoko’s average speed? Express your answer in mixed number.
Time that the Yoko's father started driving = 2.35 p.m.
Duration that Yoko's father drove from 2.35 p.m. to 7.35 p.m. = 5 h

Distance that Yoko's father travelled
= 5 x 88
= 440 km

Distance that Yoko travelled by the time her father reached the city
= 440 - 6
= 434 km

Time that Yoko took to travel 434 km = 8 h

Yoko's average speed
= 434 ÷ 8
= 54¹₄ km/h

Answer(s): 54¹₄ km/h