Mrs Loo left home at 7 a.m. and drove towards the city. 3³₄ hour later, Mr Loo left the house and drove at an average speed of 103 km/h towards the city. When Mr Loo reached his destination at 3 p.m., Mrs Loo was 24 km away from the city. Find Mrs Loo’s average speed in km/h. Express your answer in mixed number.
1 h = 60 min 
³₄ h = ³₄ x 60 = 45 min
3³₄ = 3 h 45 min

3 h 45 min after 7 a.m. = 10.45 a.m.

Time that Mr Loo left the house = 10.45 a.m.

Time that Mr Loo took from 10.45 a.m. to 3 p.m. to reach his destination = 4 h 15 min

1 min = ¹₆₀ h
15 min = ¹⁵₆₀ h = ¹₄ h
4 h 15 min = 4¹₄ h

Distance that Mr Loo drove
= 4¹₄ x 103
= 437³₄ km

Distance that Mrs Loo drove when Mr Loo reached
= 437³₄ - 24 
= 413³₄ km

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

Mrs Loo's average speed
= 413³₄ ÷ 8
= 51²³₃₂ km/h

Answer(s): 51²³₃₂ km/h