### Home > CALC > Chapter Ch11 > Lesson 11.2.4 > Problem 11-85

11-85.

This is the area under *b*′.

You computed the total books check out in part (a).

What is the total number of hours?

11-85.

This is the area under *b*′.

You computed the total books check out in part (a).

What is the total number of hours?