How do you convert $ 240 $ into ft?

Hint: Convert the given value in the required specific units by using the conversion equation. Use the formula - $ 12{\text{ inches}} = 1{\text{ feet}} $ . Place the relation for the given number and simplify the equation using the basic mathematical calculations.

Complete step-by-step answer:
We know the basic relation between feet and inches.
 $ 12{\text{ inches}} = 1{\text{ feet}} $
Place the value in the given value –
 $ 240{\text{ inches}} = \dfrac{{1 \times 240}}{{12}}{\text{ feet}} $
Simplify the above equation finding the factors of the terms in the above expression –
 $ 240{\text{ inches}} = \dfrac{{20 \times 12}}{{12}}{\text{ feet}} $
Common factors from the numerator and the denominator cancel each other and therefore remove from the numerator and the denominator.
 $ 240{\text{ inches}} = 20{\text{ feet}} $
This is the required solution.
So, the correct answer is “20”.

Note: It is very important to know the difference between the system of units and the conversional ratios between them. Since if we say mass of one it does not make any sense, also length of one feet and one inch differs a lot.
 Also, remember the conversional relations of the different physical quantities and apply accordingly. This conversion is most important in dealing with the physical quantities expressed with different systems of units.