Alright, lets get started.
(A) The total length of backyard is = 
The total width of backyard is = 
Hence total area of backyard = 
Hence total area of backyard
square feet
Now area of Patio
square feet
Now area of walkway
square feet
Now area of garden
square feet
Total area of Patio, walkway and garden
Total area of Patio, walkway and garden
square feet
So, percent of the total area of Hal’s backyard is taken up by the patio, walkway, and garden = 
percent will be
%
Means 60 % : Answer (A)
(B) One longer side of Hal’s backyard lies next to the back of his house.
So, he not need to built fence on this side.
So, rest three sides he needs fencing.
The length of rest three sides will be 
length of three sides = 33 ft
For 1 feet, it takes = $ 9.75
So, for 33 ft, it take = 
Hal spent $ 321.75 for his new fence. : Answer (B)
Hope it will help :)