A.
In the first generation we have 2 ancestors.
In the second generation we have 4 ancestors or

ancestors.
In the third generation we have 8 ancestors ot

ancestors.
We can see that each succesive generation has two times more members. The sum is:

To calculate number of ancestors we can use formula <span>for the sum of a geometric sequence. Geometric sequence is sequence of numbers that differ by a certain factor. This factor is called ratio. Formula is:
</span>

<span>Where:
S -> sum
a1 -> first member of a sequence
r -> ratio
n -> number of elements
For this question:
a1 = 2
r = 2
n = 40
</span>

<span>
b.
1 generation = 25 years
40 generations = 40 * 25 = 1000 years
c.
Total number of people who have ever lived = </span>

Number of ancestors in 40 generations =

The number of ancestors is greater than total number of people who have ever lived. This means that not all ancestors were distinct and that in each generation both men and women had children with more than one partner.
Answer:
y=8.94
Step-by-step explanation:
use the formula: a^2+b^2=c^2
64+y^2=144
y=
or y=8.94
To solve for AC in the given inscribed angle we proceed as follows:
An inscribed angle is an angle with its vertex "on" the circle formed by two intersecting chords as in our drawing. Thus here we shall use the formula:
Inscribed Angle=1/2 intercepted Arc
thus
m∠ABC=1/2mAC
thus plugging in our values we shall have:
4x-3.5=1/2(4x+17)
4x-3.5=2x+8.5
solving simplifying and solving for x we obtain
4x-2x=8.5+3.5
2x=12
hence
x=12/2
x=6°
Answer:
7.5 ft³/min
Step-by-step explanation:
Let x be the depth below the surface of the water. The height, h of the water is thus h = 10 - x.
Now, the volume of water V = Ah where A = area of isosceles base of trough = 1/2bh' where b = base of triangle = 4 ft and h' = height of triangle = 1 ft. So, A = 1/2 × 4 ft × 1 ft = 2 ft²
So, V = Ah = 2h = 2(10 - x)
The rate of change of volume is thus
dV/dt = d[2(10 - x)]/dt = -2dx/dt
Since dV/dt = 15 ft³/min,
dx/dt = -(dV/dt)/2 = -15 ft³/min ÷ 2 = -7.5 ft³/min
Since the height of the water is h = 10 - x, the rate at which the water level is rising is dh/dt = d[10 - x]/dt
= -dx/dt
= -(-7.5 ft³/min)
= 7.5 ft³/min
And the height at this point when x = 8 inches = 8 in × 1 ft/12 in = 0.67 ft is h = (10 - 0.67) ft = 9.33 ft