If we know that 30% of the time is used after 9 minutes we can write this mathematically as:

By solving for x we can determine the total time allowed to play games and so:

The total time allowed to play games is 30 minutes. Since 9 minutes have lapsed 30-9=21 minutes left to play.
yellow car = x
white cars = 9x ( 9 times as many white cars)
9x +x = 40
10x = 40
x = 40/10 =4
4 yellow cars
9*4 = 36 white cars
Net pay = $453.10
Gross pay = $734
Take home percent of the gross pay = (453.10/734) * 100
= 61.73%
From the above deduction, it can be easily concluded that the Take-Home percent of the Gross Pay is 61.73%. I hope that this is the answer that you were looking for and the answer has actually come to your desired help.
So x=x
and y=pounds
when x=0, y=64
when x=1, y=63.1
to find slope, (y1-y2)/(x1-x2)=(64-63.1)/(0-1)=0.9/-1=-0.9=slope
y=-0.9x+b
subsitute
64=-0.9(0)+b
b=64
y=-0.9+64
so int 2001, x=11
y=-0.9(11)+64
y=-9.9+64
y=54.1