Question

(1). Suppose that the distance of a car travels varies directly. with the amount of gasoline it uses. a certain car uses 17 gallons of gasoline to travel 476 mi. how many miles can the car travel if it has 15 gallons of gasoline?

Answer 1

`\begin{gathered} \text{Let 'D' represent the distance travelled by the car} \\ \text{Let 'A' represent the amount of gasoline it uses.} \end{gathered}`
`\begin{gathered} \text{Thus,} \\ D\propto A \\ D=KA\text{ where 'K' is a constant} \end{gathered}`
`\begin{gathered} \text{when D=476 miles, A=17 gallons} \\ \text{Thus,} \\ D=KA \\ 476=K*17 \\ K=(476)/(17) \\ K=28 \end{gathered}`
`\begin{gathered} We\text{ are to find 'D' when 'A' is 15 gallons} \\ \text{Thus,} \\ D=KA \\ D=28*15 \\ D=420\text{ miles} \end{gathered}`

Hence, the number of miles traveled by car, when it has gasoline of 15 gallons is 420 miles