Mrs Ee left home at 7 a.m. and drove towards the city. 1²₃ hour later, Mr Ee left the house and drove at an average speed of 95 km/h towards the city. When Mr Ee reached his destination at 3 p.m., Mrs Ee was 21 km away from the city. Find Mrs Ee’s average speed in km/h. Express your answer in mixed number.
1 h = 60 min 
²₃ h = ²₃ x 60 = 40 min
1²₃ = 1 h 40 min

1 h 40 min after 7 a.m. = 8.40 a.m.

Time that Mr Ee left the house = 8.40 a.m.

Time that Mr Ee took from 8.40 a.m. to 3 p.m. to reach his destination = 6 h 20 min

1 min = ¹₆₀ h
20 min = ²⁰₆₀ h = ¹₃ h
6 h 20 min = 6¹₃ h

Distance that Mr Ee drove
= 6¹₃ x 95
= 601²₃ km

Distance that Mrs Ee drove when Mr Ee reached
= 601²₃ - 21 
= 580²₃ km

Time that Mrs Ee took to travel from 7 a.m. to 3 p.m. = 8 h

Mrs Ee's average speed
= 580²₃ ÷ 8
= 72⁷₁₂ km/h

Answer(s): 72⁷₁₂ km/h