The answer is: 5,614 square inches.
The explanation is shown below:
1. The gift on the bottom is a rectangular prism. To calculate its surface area, you must apply the following formula:
![SA=2[(l)(w)+(l)(h)+(h)(w)]](https://tex.z-dn.net/?f=SA%3D2%5B%28l%29%28w%29%2B%28l%29%28h%29%2B%28h%29%28w%29%5D)
Where 
is the length (20 inches), 
is the width (42 inches) and 
is the heigth (16 inches).
2. Substitute values:
![SA1=2[(20in)(42in)+(20in)(16in)+(16in)(42in)]=3,664in^{2](https://tex.z-dn.net/?f=SA1%3D2%5B%2820in%29%2842in%29%2B%2820in%29%2816in%29%2B%2816in%29%2842in%29%5D%3D3%2C664in%5E%7B2)
3. The surface area of the other gifts can be calculated with the formula for calculate the surface area of a cube:
Where 
is the side.
4. The surface area of the bigger cube is:
5. The surface area of the smaller cube is:
6. The total surface area (the combined surface area of the three gifts) is:
Answer:
c 35%
Step-by-step explanation:
2 green,5 yellow, 6 red,and 7 blue marbles
2+5+6+7 = 20 marbles
P(blue) = blue marbles / total marbles
= 7/20
= 35/100
=35%
The answer is D
Type 1 Type 2 plants have somewhat similar height distributions
Answer:
the question is incomplete, so I looked for a similar one:
<em>After the release of radioactive material into the atmosphere from a nuclear power plant, the hay was contaminated by iodine 131 ( half-life, 8 days). If it is all right to feed the hay to cows when 10% of the iodine 131 remains, how long did the farmers need to wait to use this hay? </em>
iodine's half life (we are given x, we need to find b):
0.5A₀ = A₀eᵇˣ
x = 8 days
we eliminate A₀ from both sides
0.5 = eᵇ⁸
ln 0.5 = ln eᵇ⁸
-0.69315 = b8
b = -0.69315 / 8 = -0.08664
since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):
0.1A₀ = A₀eᵇˣ
0.1 = eᵇˣ
ln 0.1 = bx
where b = -0.08664
x = ln 0.1 / -0.08664 = -2.302585 / -0.08664 = 26.58 days
