Question

How many miles are in 100 feet? \[\]

Answer 1

Hint: We recall the definition of miles and feet. We recall the conversion that 1 miles is equal to $5280$ feet. We use a unitary method and find numbers of miles in 1 foot and then multiply 100 with it to get the asked result. \[\]

Complete step-by-step solution:
We know that the unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying or dividing the single unit value. There are two types of unitary method one is direct variation and other is indirect variation.
When one quality $a$ increases with another quantity $b$ and also $a$ decreases with $b$ then we say the quantities $a$ and $b$ are in direct variation. We divide the increasing quantity $a$ by $b$ to obtain the value of a single unit and then multiply to find the required value. \[\]
We know that miles is the imperial unit for long distance measurement and feet is the imperial unit to measure short distance. We know that 1 miles is equal to $5280$ feet which means 5280 feet have 1 mile. The number of feet is more in the mile. So we divide 1 mile by 5280 by decimal division to get number of miles in 1 foot as
\[\dfrac{1}{5280}=0.001893\]
We are asked to find how many miles are in 100 feet. So we multiply 100 and find the required result as \[100\times \dfrac{1}{5280}=100\times 0.0001893=0.01893\text{ miles}\]

Note: We note that we require decimal division to find $\dfrac{1}{5280}$. We can find an approximate with more digits as $\dfrac{1}{5280}=0.00018939393...=0.00018\overline{93}$. We note that 1 foot is further divided into 12 inches. Both miles and feet are not used as units for scientific calculation as they are not SI units unlike metre which is the SI unit.