Question

How many feet are there in \[4\] miles?

Answer 1

Hint: We know that \[1\] mile = \[5280\] feet.Both miles and feet are units for measuring distance. Using a unitary method we can find an answer.

Complete step-by-step answer:
\[1\] mile = \[5280\] feet … (1)
The above equation states that there are \[5280\] feet in a mile.
To find the number of feet in \[4\] miles, we use the unitary method. Unitary method states that first, the unit value of s quantity is determined and then the required value is found by multiplying it with the unit value.
Here unit value or value of \[1\] mile is equal to \[5280\] feet.
The value of \[4\] miles needs to be found.
Therefore multiply both sides of the equation (1) by \[4\]:
\[\left( {4 \times 1} \right)\] miles \[ = \] \[\left( {4 \times 5280} \right)\] feet.
\[ \Rightarrow \] \[4\] miles \[ = \] \[21120\] feet.
Hence, there are \[21120\] feet in \[4\] miles.

Additional information:
For example a mile is a unit used to measure road distances as it is a large unit while feet being a smaller unit is used for measuring quantities like height of people. The unit mile is symbolised by “mi” while feet is symbolised by “ft”.

Note: Also remember the conversion from feet to mile. \[1\] foot (singular of feet) \[ \approx \] \[18.9 \times {10^{ - 5}}\] miles. To verify the above conversion, the answer obtained above can be rechecked.
\[1\] foot \[ \approx \] \[18.9 \times {10^{ - 5}}\] miles
\[\therefore \]\[21120\] feet \[ \approx 18.9 \times {10^{ - 5}} \times 21120\] miles.
\[ \Rightarrow \] \[21120\] feet \[ \approx \] \[3.99\] miles \[ \approx \] \[4\] miles.
Hence, verified.
“\[ \approx \]” is the approximate symbol which means that the value is very close, not something, this symbol is generally used for decimal values. As seen above we wrote \[3.99 \approx 4\], that means \[3.99\] is exactly not equal to \[4\] but is very close to the value \[4\].