To make 2/5 into a fifteenth, you have to multiply the 5 by 3 to get 15. Whatever you do to the top you have to do to the bottom, meaning that you have to multiply 2 by 3 to get 6 on top.
To make 2/3 into a fifteenth, you have to multiply the 3 by 5 to get 15. Whatever you do to the top you have to do to the bottom, meaning that you have to multiply 2 by 5 to get 10 on top.
This is the same rule for all equations involving fractions.
The formula for volume of a sphere is V=(4pi*r^3)/3. Plugging in 12 for r we get V=(4pi*(12)^3)/3 V=(4pi*1728)/3 V=(6912pi)/3 V=2304pi Round to 2 decimal places: 7238.23 Final Answer: 7238.23 cubic units. Hope I helped :)
