$A$ train,$300 \, m$ long,passes a man walking along the line in the same direction at the rate of $3 \, km/h$ in $33 \, s$. The speed of the train is (in $km/h$):

$A$ man travels $600 \, km$ by train at $80 \, km/hr$, $800 \, km$ by ship at $40 \, km/hr$, $500 \, km$ by aeroplane at $400 \, km/hr$, and $100 \, km$ by car at $50 \, km/hr$. What is the average speed for the entire distance? (in $km/hr$)

Two men start together to walk a certain distance,one at $4 \, km/h$ and another at $3 \, km/h$. The former arrives half an hour before the latter. Find out the distance in $km$.

Two trains of equal length take $10\, seconds$ and $15\, seconds$ respectively to cross a telegraph post. If the length of each train is $120\, metres,$ in what time (in $seconds$) will they cross each other when travelling in opposite directions?

$A$ cyclist,after cycling a distance of $70 \,km$ on the second day,finds that the ratio of distance covered by him on the first two days is $4:5$. If he travels a distance of $42 \,km$ on the third day,then the ratio of distances travelled on the third day and the first day is:

Deepa drives a bike at an average speed of $30 \, km/h$ and reaches her destination in $6 \, hours$. Hema covers that same distance in $4 \, hours$. If Deepa increases her average speed by $10 \, km/h$ and Hema increases her average speed by $5 \, km/h$,then what will be the difference in time taken by them to reach their destination?