Answer: He still owns 64% of the Mr.Williams' original parking.
Step-by-step explanation:
Let x = Area of the original parking plot.
First he sold 20% of his lot to neighbor .
Sold plot = 20% of x = 0.20x [Replace 'of' by '×' and divide number by 100 to remove %]
Reminder= x-0.20x= (1-0.20)x=0.80x
Again he sold 20% of the remainder .
Sold plot = 20% of (0.80x) = 0.20 (0.80x)
= 0.16x
Remainder plot = 0.80x-0.16x= 0.64x
Percent of Mr.Williams' original parking lot does he still own =
Hence, he still owns 64% of the Mr.Williams' original parking.