Commercial Arithmetics : Speed, Time, Distance

maths > commercial-arithmetics

Speed, Time, Distance

what you'll learn...

overview

An example to the rate $\times$ $xx$ span $=$ $=$ aggregate, is
speed $\times$ $xx$ 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 $\frac{102}{3}$ $102/3$ $= 34$ $=34$ 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 $\times$ $xx$ 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 $\times$ $xx$ 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 $\times$ $xx$ 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 $\times$ $xx$ time $=$ $=$ distance.
Speed and Distance are in direct variation.

The distance traveled $= \frac{25}{10} \times 12 = 30$ $=25/10 xx 12 = 30$ 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 $\times$ $xx$ time $=$ $=$ distance.
Speed and time are in inverse variation.

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

summary

Problems in Speed-Time-Distance : Simplify the problem to
speed $\times$ $xx$ 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

The outline of material to learn "commercial arithmetics" is as follows.

Note: Click here for the detailed ouline of commercial arthmetics.

• Ratio, Proportion, Percentage

→ Comparing Quantities

→ Introduction to Ratio

→ Ration & Fraction Differences

→ ProportionsP

→ Percentages

→ Conversion to percentage

• Unitary Method

→ Introduction to Unitary Method

→ Direct Variation

→ Inverse Variation

→ DIV Pair

• Simple & Compound Interest

→ Story of Interest

→ Simple Interest

→ Compound Interest

• Rate•Span=Aggregate

→ Understanding Rate-Span

→ Speed • Time=Distance

→ Work-rate • time = Work-amount

→ Fill-rate • time = Filled-amount

• Profit-Loss-Discount-Tax

→ Profit-Loss

→ Discount

→ Tax

→ Formulas