There are 15,500 sheets of paper
8r and 4r are like terms since they both have an r
also 3s and -3s are also like terms because of the s
In cylindrical coordinates, we have
, so that

correspond to the upper and lower halves of a sphere with radius
. In spherical coordinates, this sphere is
.
means our region is between two cylinders with radius 1 and
. In spherical coordinates, the inner cylinder has equation

This cylinder meets the sphere when

which occurs at

where
. Then
.
The volume element transforms to

Putting everything together, we have

Answer:
600 m
Step-by-step explanation:
You know that she walks 1 meter in 1 second, but they're asking about minutes. Since 60 seconds are in 1 minute, it means she was 60 meters in 1 minute. Then multiply that by 10 (10 minutes).
She walked 600 meters, in 10 minutes.
I hope this helped!