Time, Speed and Distance

A boy goes to a place with a speed of $a> km/h$ and comes back with a speed of $b> km/h$. The constant speed with which he should travel to cover the entire distance in the same total time is

By increasing the speed of the car by $10 km/hr$ the time of journey for a distance of $72 km$ is reduced by $36$ minutes. Find the original speed of the car.

A bird files with a speed $v=\left| t-2 \right| \;m/{ s}$ along a straight line, where $t$ is the time in seconds. The distance travelled by the bird during first four seconds is equal to

If a person rowing at the rate of $5>$ km/h in still water, takes thrice as much time in going $40> \ km$ upstream as in going $40> \ km$ downstream, then the speed of the stream, is:

Two stations A and B are $90$ km apart and on a highway. A car starts from A and another from B at the same time. If they go in the same direction, they meet after $9$ hours and if they go in opposite directions, they meet after $\displaystyle 1\frac{2}{7}$ hours. Find the speeds of both the cars.

The distance between two towns is $300$ km. Car $A$ and Car $B$ starts simultaneously from these towns and move towards each other. The speed of Car $A$ is more than that of Car $B$ by $7$ km/h. If the distance between the cars after two hours is $34$ km. Find the speed of both cars.

A train covered a certain distance at a uniform speed. If the train would have been 10km/h faster, it would have taken 2 hours less than the scheduled time. And, if the train were slower by 10km/h ; it would have taken 3 hours more than the scheduled time. The distance covered by the train is ..................

A cyclist cycles non-stop from $A$ to $B$ a distance of $14$ km at a certain average speed. If his average speed reduces by $1$ km/hr, then he takes $\displaystyle \frac{1}{3}$ hour more to cover the same distance. What was the original average speed of the cyclist?

In covering a distance of $30km$. Amit takes $2hrs.$ more than suresh. If Amit doubles his speed, he would take one hour less than suresh. Amit's speed is

A part of a journey is covered in $1$ hour $40$ minutes at $75$ km/hr and the remaining part of it is covered in $2$ hours $50$ minutes at $60$ km/hr. Find the average speed during the whole journey.

A man can row a boat in still water at the rate of 6 km per hour. If the stream flows at the rate of 2 km/hour, he takes half the time going downstream than going upstream the same distance. His average speed for upstream and down stream trip is -

A boat goes downstream and covers the distance between two ports in 4 hours, while it covers the same distance upstream in 5 hours. If the speed of the stream is 2 km/hr, find the speed of boat in still water.

X and Y are two towns. A man goes from town X to town Y at an average speed of $30$ km per hour and returns at an average speed of $20$ km per hour. Find the distance between the two towns if a man takes $10$ hours on the whole.