maths > commercial-arithmetics

Speed, Time, Distance

what you'll learn...

overview

An example to the rate $×$$\times$ span $=$$=$ aggregate, is
speed $×$$\times$ time $=$$=$ distance.

This is explained in detail.

examples in speed

A train covers $102$$102$km in $3$$3$ hours.

The speed of the train is $34$$34$km per hour.

Unitary method in Speed-Time-Distance:
The distance traveled in $1$$1$ unit time is the speed.

A train covers $102$$102$km in $3$$3$ hours.
The speed of the train is $\frac{102}{3}$$\frac{102}{3}$ $=34$$= 34$ km per hour.

How much time does a train, at the speed of $60$$60$ km per hour, take to cross $240$$240$km?

Speed $×$$\times$ time $=$$=$ distance.

Speed and distance are given. Time is to be calculated.

time $=240/60=4$$= 240 / 60 = 4$ hours.

What distance a train at the speed $50$$50$ km per hour covers in $7$$7$ hours?

Speed $×$$\times$ time $=$$=$ distance.

Speed and time are given. Distance is to be calculated.

distance $=350$$= 350$km

A car takes $3$$3$ mins to cross a distance $30$$30$ meters. How much distance it would cover if it travels for $22$$22$ mins?

Speed $×$$\times$ time $=$$=$ distance.
Time and Distance are in direct variation.

Distance traveled $=220$$= 220$m

A car going at the speed $10$$10$ meter per second crosses $25$$25$ meters in the given time. If the speed is increased to $12$$12$ meter per second, what distance it travels in the same time?

Speed $×$$\times$ time $=$$=$ distance.
Speed and Distance are in direct variation.

The distance traveled $=\frac{25}{10}×12=30$$= \frac{25}{10} \times 12 = 30$m

A car takes $3$$3$mins to cross a bridge at $10$$10$ meter per second. What is the time it takes to cross the bridge at $20$$20$ meter per second?

Speed $×$$\times$ time $=$$=$ distance.
Speed and time are in inverse variation.

The time taken $=3×\frac{10}{20}=1.5$$= 3 \times \frac{10}{20} = 1.5$min

summary

Problems in Speed-Time-Distance : Simplify the problem to
speed $×$$\times$ time $=$$=$ distance

There are three quantities in the equation. Possible formulation of questions are

•  two quantities are given, and the third is asked.

•  two quantities are given. Under the condition that one of the given is modified, the changed second is asked. (direct or inverse variation)

Outline