Question

The parking charges of a car in a parking lot is rs. 20 for the first3 hours and rs. 10 for subsequent hours. Taking total parking time to be x hours and total charges as rs. y, write a linear equation in two variable to express the above statement also find the parking charges for five hours.

Answer 1

For no of hours equal to or more than 3, the equation is y = 10(x-3) + 20

or in simplified form , y = 10x - 10

The cost for five hours = Rs.40

-its given that the cost is 20 for the first 3 hours, so if x=1 or 2 , cost=20

- if the hours are 3 or more than 3, it costs Rs.10 for every extra hour

- This means if x is the no of hours, for each x-3 hours,  it costs Rs.10

- Upon this, the cost of first 3 hours is also added

-Hence we get the equation, y= 10(x-3) +20

-To find the cost for 5 hours,

we put x=5 in our equation,

y=10(5-3)+20 = 40