Question

The portion of a student’s ballpoint pen that contains the ink is a cylinder with a diameter of 0.400 cm and a height of 11.5 cm. If the ink lasts 7 weeks, what is the volume of ink that the student uses each week?

Answer 1

To find the volume of a cylinder, you have to do pi x radius squared x height. So in this case, you would find the radius by dividing the diameter by two. Then you would set up your equation: pi x 0.2 squared x 11.5. Then you will get an answer of about 1.4. So the volume of the ink the student uses each week would be 1.4 cm cubed.

Answer 2

The volume of ink that the student uses each week is 0.20 cm³.

Explanation:

Diameter of he cylinder is 0.400 cm and height is 11.5.

`r=(d)/(2)={0.4}{2}=0.2`

`h=11.5`

Volume of cylinder is

`V=\pi r^2h`

`V=\pi * (0.2)^2* (11.5)`

`V=1.445`

The volume of cylinder is 1.445 cm³. It means the volume is ink is 1.445 cm³.

It is given that ink lasts 7 weeks. So, the volume of ink that the student uses each week is

`(1.445)/(7)=0.2064\approx 0.20`

Therefore the volume of ink that the student uses each week is 0.20 cm³.