Question

The number of cars (c) in a parking lot increases when the parking lot fee (f) decreases. Right there correct equation for the scenario, and for the number of cars when the fee is six dollars.

Answer 1

If fee be y and cars be x

`\\ \bull\tt\longmapsto x\propto (1)/(y)`

`\\ \bull\tt\longmapsto x_1y_1=x_2y_2`

`\\ \bull\tt\longmapsto 30(10)=x_2(6)`

`\\ \bull\tt\longmapsto 300=6x_2`

`\\ \bull\tt\longmapsto x_2=(300)/(6)`

`\\ \bull\tt\longmapsto x_2=50`

Answer 2

This is an inverse proportionality

`{ \tt{c \: \alpha \: - (1)/(f) }} \\ \\ { \tt{c = - (k)/(f) }}`

• k is a constant of proportionality

• when c is 15, f is 20, therefore;

`{ \tt{15 = ( - k)/(20) }} \\ \\ { \tt{ - k = 20 * 15}} \\ \\ { \tt{k = - 300}}`

• Therefore, the equation is :

`{ \boxed{ \bf{c = ( - 300)/(f) }}}`

→ when f is 10:

`{ \tt{c = ( - 300)/(10) }} \\ \\ { \tt{c = - 30}}`

negative shows decrease