Answer:
144 people were originally at the party.
Step-by-step explanation:
18 boys is one fifth of the second boys population, so the second population is 18x9 = 162. The original population would be 162-18, which equals 144.
4.) The lateral area of a figure is the area of the figure with the exception of the bases.
Given a prism with right triangle bases, the lateral area of the prism is the sum of the areas of the rectangles making up the prism.
This is given by
Lateral area = (8.94)(41) + (4)(41) + (8)(41) = 366.54 + 164 + 328 = 858.54 ≈ 859 m^2
The surface area is the sum of the bases plus the lateral area. The area of a rectangle is given by half base times height.
Surface area = 1/2 x 8 x 4 + 1/2 x 8 x 4 + 859 = 16 + 16 + 859 = 891 m^2
5.) The surface area of a cylinder is given by pi r^2h where r is the radius = 12 inches and h is the height = 17 inches.
Surface area = π x (12)^2 x 17 = 2,448π = 7,690.62 in^2 ≈ 7,691 in^2
Hundredths place=9
Ones place=6
I will show you how to do #5:
a). -20 + 2(n-1) Original Expression
-20 +2n - 2 Distributive Property
-22 + n Combine Like Terms
Final Expression: -22 + n
b). 1.5 + (-2.5)(n -1) Original Expression
1.5 + -2.5n + 2.5 Distributive Property
4 - 2.5n Combine Like Terms
Final Expression: 4 - 2.5n
