Hazel left home at 11.50 a.m. and drove towards the city. 2 hours later, her father left their home and drove towards the same city at 100 km/h. When the father reached the city at 4.50 p.m., Hazel had another 4 km to travel. What was Hazel’s average speed? Express your answer in mixed number.
Time that the Hazel's father started driving = 1.50 p.m.
Duration that Hazel's father drove from 1.50 p.m. to 4.50 p.m. = 3 h

Distance that Hazel's father travelled
= 3 x 100
= 300 km

Distance that Hazel travelled by the time her father reached the city
= 300 - 4
= 296 km

Time that Hazel took to travel 296 km = 5 h

Hazel's average speed
= 296 ÷ 5
= 59¹₅ km/h

Answer(s): 59¹₅ km/h