Which of the following statements correctly describe how the geologic time scale is divided?
///Check all that are true.///

The geologic time scale is made up of days, months, and years.

Each era on the geologic time scale lasts for a different amount of time.

Each era on the geologic time scale lasts for the same amount of time.

The geologic time scale is divided based on major events in Earth’s history.

With math question will mark brainliest question in the pic.

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.