The sum formula for a geometric sequaence is:
sum(n) = a1(1-r^n)/1-r
Where n is the number of terms, a1 is the first term and r is the common ratio:
s(8) = 3(1-1/2^8) / (1-1/2)
s(8) = 3(1-1/256) / 1/2
s(8) = 2 253/256 / 1/2
s(8) = 765/128
The answer is C.
Answer:
His sales that week were $2,160.
Step-by-step explanation:
First, you have to subtract $324 from the amount he earned that week, to find the 5% he got from sales:
$432-$324=$108
Now, you know that he received $108 that represent 5% of his sales and you can use a rule of three to find the amount that represents 100% which would be his sales that week:
5% → 108
100% → x
x=(100*108)/5=2160
According to this, the answer is that his sales that week were $2,160.
There’s no slope through (5,-4)
6. It is asking you to find the surface area for this one:
1 litre = 0.001 cubic meters
15.4 litres = 0.0154 cubic meters
The volume of the cylinder has to be 0.0154m^3.
V = (pi(r)^2)h
0.0154 = (pi(r)^2)(1)
r^2 = 0.0154/pi
r = 0.07m
Surface Area of Circles on Bottom:
A = pi(r)^2
A = pi(0.07)^2
A = 0.0154
0.0154*2 = 0.0308m^2
Surface Area of Walls:
This will be the circumference of the circle times the height, since the walls are just like a big rectangle.
C = 2pi(r)
C = 2pi(0.07)
C = 0.44m
0.44*1 = 0.44m^2
Finally, add the two surface areas:
0.44 + 0.0308 = 0.47m^2
You will need 0.47m^2 of sheet metal to make this cylinder.
7. Find the volume of everything and just the graphite, and subtract the graphite’s volume from everything to get just the wood. The volume of a cylinder is pi((r)^2)h.
Everything:
Watch out for units, since the diameter is in mm and the length is in cm.
r = 3.5mm or 0.35cm
V = pi((0.35)^2)(14)
V = 5.34cm^3
Graphite:
r = 0.5mm or 0.05cm
V = pi((0.05)^2)(14)
V = 0.11cm^3
5.34 - 0.11 = 5.23cm^3
8. For this problem, it wants your answer in cm^3. Find the volume of one bowl and multiply it by 250:
r = 3.5cm
V = pi((3.5)^2)(4)
V = 153.94cm^3
153.94*250 = 38484.51cm^3 of soup needed.
I sure hope that I didn’t confuse you too much with all of my math gibberish (sorry). Please let me know if there is anything else that I can help with. Have a nice day
