Question

How many centimeters are in $7.2$ inches ?

Answer 1

Hint: Here we will use the concept of the conversion of units. We are asked to convert $7.2$ inches into centimeters. To convert the units we will use the relationship between inches and centimeters which is given by $1\,\,{\text{inch = 2}}{\text{.54}}\,\,{\text{cm}}$. Then to get the required value we will multiply both sides of the conversion equation by $7.2$ and it converts inches into centimeters.

Complete step by step solution:
The given length is $7.2$ inches.
We have to calculate how many centimeters does $7.2$ inches contain.
Note that the inches is a length measuring unit.
Firstly, we will write the basic conversion of the length unit of inches into centimeters.
The relationship between inches and centimeters is given by a conversion equation, $1\,\,{\text{inch = 2}}{\text{.54}}\,\,{\text{cm}}$
As the length is given $7.2$ inches, we will multiply both sides of the above equation by $7.2$.
Hence we get,
$7.2\, \times \,1\,\,{\text{inch}}\,\,{\text{ = }}\,{\text{7}}{\text{.2}} \times {\text{2}}{\text{.54}}\,\,{\text{cm}}$
Now we will simply perform the multiplication in the above equation we get,
$ \Rightarrow 7.2\,\,{\text{inches}}\,\, = \,18.288\,\,{\text{cm}}$
Note that $18.288 \approx 18.29$
$ \Rightarrow 7.2\,\,{\text{inches}}\,\,{\text{ = }}\,{\text{18}}{\text{.29}}\,\,{\text{cm}}$.

Therefore the length $7.2$ inches is equal to $18.29\,\,{\text{cm}}$.

Note: To convert a dimension given in one unit into another unit we have a converting factor.
Here to convert inches into centimeters we have, $1\,\,{\text{inch = 2}}{\text{.54}}\,\,{\text{cm}}$.
Generally, for converting some dimensions into smaller units of measurement, we will divide it with the converting factor and for converting some dimension into larger units we will multiply it with the converting factor. So in the above problem we need to multiply by $2.54$, since the centimeter is larger than inches.
To solve these types of questions students must have the basic knowledge inches and centimeters and the relationship between them. The given question is simple, so avoid any calculation mistakes. Otherwise it gives incorrect answers.
Note that to convert centimeters into inches we need to divide the given value by $2.54$.