Question

How many millimetres are there in $ 3\;Km $ ?

Answer 1

Hint: To solve this, we should know the order in which one has to consider to solve this problem. Step by step proceeding will help you to get the answer. Try to reduce the $ 3\;Km $ in an orderly manner, so that you are able to understand the question and answer it properly.

Complete step-by-step answer:
There are a number of scales for doing measurements, one differs from the other by means of $ {10^x} $ . Here consider the given question, which is $ 3\;Km $ , now we have to reduce it to meters, in which we know that $ 1\;Km $ is equal to $ 1000\;m $ . If we write $ 3\;Km $ in terms of meters, it will be equal to $ 3000\;m $ . When we look furthermore in this problem, now we have to consider it in terms of centimetre, which is known to us as 1 meter is equal to $ 100\;cm $ . Now, if we convert 3000m into centimetre we get $ 300000\;cm $ . And at last, we have one more step to deal with, let’s define $ 1 $ $ \;cm $ in terms of millimetre, which will be equal to $ 10\;mm $ . Therefore, when we apply it to $ 300000\;cm $ we get, $ 3000000\;mm $ .
 $ 3km = 3000000\;mm $
This is our required solution.
So, the correct answer is “ $ 3km = 3000000\;mm $ ”.

Note: We come up with many numbers of scale either to measure too large or too small objects. It will be convenient for us, if we choose the right scale to measure a particular value. For instance, if we need to measure a diameter of a wire it will be convenient if we measure it in a millimetre. On the other hand, if we want to measure a distance between two cities, it will be convenient if we measure it in kilometres.