How do you come to this result, my final amount comes to 11701.2728 cm3 instead? Where am I going wrong? Thanks

embizze | High School Teacher | (Level 1) Educator Emeritus

Posted on

To determine the capacity of the beer jug, we'll have to compute the volume of the conical frustum:

, where r1 is the radius of top diameter and r2 is the radius of bottom diameter.

We'll calculate the radii r1 and r2:

r1 = 14.6/2

r1 = 7.3 cm

r2 = 12/2

r2 = 6 cm

The height of the conical frustum is: h = 28 cm.

Now, we'll calculate the volume:

Now, we'll convert cube centimeters in liters.

We know that 1 cubic centimeter = 0.001 liters, therefore the liter capacity of the beer jug is of 1.242173 liters.

The original answer of 1.242173 liters appears to contain an arithmetic mistake.

`(28*pi*(7.3^2+6^2+7.6*6))/(3)=(28*pi*133.09)/(3)`

If you do not round pi you will get 11707.2078555/3=3902.4 cm^3
If you round pi to 3.14 you will get 11701.2728/3= 3900.4 cm^3

so the answer should be approximately 3.9 liters.

snake-za | eNotes Newbie

Posted on

Here is the link to the original equation.

http://www.enotes.com/math/q-and-a/how-do-work-out-litre-capacity-beer-jug-top-276310

Thanks!