Question

Using a measuring scale (15cm scale), the length AB =3m and breadth BC = 2m for a rectangle are found. Find the length and breadth of the given rectangle in mm.
A. 3000, 2000
B. 300, 200
C. 3, 2
D. 30, 20

Answer 1

Hint: In order to answer this question, all you have to know is how to convert the measurement given in meters to millimeters. You may already know that milli is added to the SI unit of length as a prefix indicating a certain power of ten. Recall the conversion and hence convert the given measurements of length and breadth to millimeters.

Formula used: Conversion of meters to millimeters,
$1m={{10}^{3}}mm$

Complete step by step answer:
In the question, we are given the measurements of length and breadth of a rectangle made by using a measuring scale of 15cm. We are asked to convert the given measurements of length and breadth into millimeters.
Here the measurements are given in meters. We know that meter (m) is the SI unit of length and ‘milli’ is the prefix added to meters to indicate ${{10}^{-3}}$. That is,
$1mm={{10}^{-3}}m$
$\Rightarrow 1m={{10}^{3}}mm$ …………………………………….. (1)
In the question, we are given the length of the rectangle in meters as,
$AB=3m$
On converting this value to millimeters using (1) we get,
$AB=3\times {{10}^{3}}mm$
$\therefore AB=3000mm$
Similarly for the given breadth of rectangle in meters,
$BC=2m$
We could convert into millimeters as,
$BC=2\times {{10}^{3}}mm$
$\therefore BC=2000mm$
Therefore, we have found the length and breadth of the given rectangle in millimeters to be 3000mm and 2000mm respectively.

So, the correct answer is “Option A”.

Note: We consider the international system of units or the SI unit system as the standard unit system. Along with milli there are other prefixes added to these SI units so as to make the measurements concise. All of these prefixes stand for one or the other powers of 10. Some of the other prefixes are,
${{10}^{-2}}$ -centi, ${{10}^{3}}$ -kilo,${{10}^{-6}}$ -micro,${{10}^{-9}}$ -nano , etc.