A calculation related to inverse proportion

A calculation related to inverse proportion

Now let's do a calculation.

If 12 workers complete a work in 10 days, in how many days will 20 workers complete the work?

How to do this calculation?

If you say that you can divide and find out how many days it will take a worker to complete the work and multiply it by 20, it will be wrong.

Note that the above calculation is inversely proportional. As the number of workers increases from 12 to 20, the working days will decrease! When one variable increases another variable decreases. So it is inverse proportion. In inverse proportion we have to multiply the variables themselves. That means people × days.

12 workers working in 10 days should be taken as 12 × 10.

Since we don't know how many days 20 workers will take to complete the work, if we take it as x, then the multiplier will be 20 × x!

Now we need to equate the two multipliers to find the value of x.

12 × 10 = 20 × x

120 = 20x

x = 120 / 20

x = 6

So if 20 workers do the work they will finish it in 6 days.

See how simple we have found the answer.

Similarly, when you do a lot of calculations, you will put the answers in your mind without the help of paper and pen and you will tell the answers in an instant.

What do we see next?

Calculations related to percentage, discount, taxation can be done easily using direct proportion. Not only is it simple but it can also be done quickly.

That's what we're going to look at next.

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