Ivory left home at 11.10 a.m. and drove towards the seaside resort. 3 hours later, her grandmother left their home and drove towards the same seaside resort at 98 km/h. When the grandmother reached the seaside resort at 7.10 p.m., Ivory had another 2 km to travel. What was Ivory’s average speed? Express your answer in mixed number.
Time that the Ivory's grandmother started driving = 2.10 p.m.
Duration that Ivory's grandmother drove from 2.10 p.m. to 7.10 p.m. = 5 h

Distance that Ivory's grandmother travelled
= 5 x 98
= 490 km

Distance that Ivory travelled by the time her grandmother reached the city
= 490 - 2
= 488 km

Time that Ivory took to travel 488 km = 8 h

Ivory's average speed
= 488 ÷ 8
= 61 km/h

Answer(s): 61 km/h