It should be C which is torus
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
You have no grounds for making a statement like that.  There are a variety of reasons why you might not get immediate answers.  Be patient.
I will do the second part of this question (finding the first three numbers):
a(4) = a(3)*(-3) + 2 = -148, so a(3)*(-3) = -150 and a(3) = -50
a(3) = 50
a(2) = a(3)*(-3) + 2 = 50, so -3*a(3) = 48 and a(d) = -16
a(1) = a(2)*(-3) + 2 = -16, so a(2)*(-3) = -18 and a(1) = 6
The procedure for finding a(5), a(6) and a(7) is exactly the same.
 
        
             
        
        
        
She bought 4, then she bought 3 more....so she bought 7 packs
each pack contains 12 pencils..
so 7 packs each containing 12 pencils ...
7(12) = 84 total pencils <===
        
                    
             
        
        
        
The wall area is the product of the room perimeter and the room height:
   A₁ = (2*(12.5 ft + 10.5 ft))*(8.0 ft) = 368 ft²
The window and door area together is
   A₂ = 2*((4 ft)*(3 ft)) + (7 ft)*(3 ft) = 45 ft²
The area of one roll of wallpaper is
   A₃ = (2.5 ft)*(30 ft) = 75 ft²
Then the number of rolls of wallpaper required will be
   1.1*(A₁ - A₂)/A₃ ≈ 4.74
5 rolls of wallpaper should be purchased.
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As a practical matter, not much of the window and door area can be saved. The rolls are 30 inches wide, but the openings are 36 inches wide. Some will likely have to be cut from two strips. The strips will have to be the full length of the wall, and the amount cut likely cannot be used elsewhere. If the window and door area cannot be salvaged, then likely ceiling(5.4) = 6 rolls will be needed (still allowing 10% for matching and waste).