Answer:
Therefore the mass of the of the oil is 409.59 kg.
Step-by-step explanation:
Let us consider a circular disk. The inner radius of the disk be r and the outer diameter of the disk be (r+Δr).
The area of the disk
=The area of the outer circle - The area of the inner circle
= 
![=\pi [r^2+2r\triangle r+(\triangle r)^2-r^2]](https://tex.z-dn.net/?f=%3D%5Cpi%20%5Br%5E2%2B2r%5Ctriangle%20r%2B%28%5Ctriangle%20r%29%5E2-r%5E2%5D)
![=\pi [2r\triangle r+(\triangle r)^2]](https://tex.z-dn.net/?f=%3D%5Cpi%20%5B2r%5Ctriangle%20r%2B%28%5Ctriangle%20r%29%5E2%5D)
Since (Δr)² is very small, So it is ignorable.
∴
The density 
We know,
Mass= Area× density

Total mass 
Therefore

![=40\pi[ln(1+r^2)]_0^5](https://tex.z-dn.net/?f=%3D40%5Cpi%5Bln%281%2Br%5E2%29%5D_0%5E5)
![=40\pi [ln(1+5^2)-ln(1+0^2)]](https://tex.z-dn.net/?f=%3D40%5Cpi%20%5Bln%281%2B5%5E2%29-ln%281%2B0%5E2%29%5D)

= 409.59 kg (approx)
Therefore the mass of the of the oil is 409.59 kg.
Answer:
70
Step-by-step explanation:
First add the tens: 20 + 30 + 10= 60
Now add the Ones: 7 + 2 + 4= 13
now add them all together: 60+13=73
so the best estimate is 70
Your Welcome
Answer:
x=2 y=1
Step-by-step explanation:
3 times 2 =6
plus 1 = 7
Answer:
hope its helpful to uh.......
So the trapezoid has 2 parallel sides making segments AD and BC transversals
Therefore making angle c and angle b add up to 180
(180-3x) + 3x + 180-9x +9x
180 +12x = 360
180= 12x
x= 15