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

First, we need to figure out the volume of the cylinder that holds the ink. The formula for the volume of a cylinder is
`\pi r^(2) h`

We have the diameter, but we can easily find the radius by dividing it by 2. 0.400/2=0.200. Now, we plug our numbers into the formula.


`\pi 0.2^(2) *11.5 = 1.445 cm^(3)`

Now, we need to figure out how much ink he uses each week. We do this by dividing the volume by the amount of weeks, or 1.445/7 = 0.206.

So, the student uses
`0.206 cm^(3)` ink each week.