Am very bad at explaining things but the answer is 8
The formula for the circumference of a circle = 2 x radius x pi
The radius is given as 21 cm and pi = 3.142
Circumference = 2 x 21 x 3.142 = 131.964 cm
The band earned $1,200.
1. Subtract the flat fee 1,200-700 =500
2. 500 is what just the band made. Divide that by .16 (16%) to get the total ticket amount... 500 divided by .16 = 3,125
The total ticket amount was $3,125.
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).
It is 320 because if you divide 1000 by 10, you would get 100 (which would be equal to 10% of 1000) So if you multiply 100x3=300. then, 2% of 100 is 20, so you add that to 300 then you 320
