the first day anna read a quarter of the book. on the second day she read a third of the remainder. noticed that after two days he had 80 pages left unread. how many pages did the book have?​

160 pages

Explanation:

Required

The number of pages

Let the number of pages be x.

So, on day 1; we have:

After day 1, there are: left ----------------- i.e x - 1/4x

On day 2, we have:

At this point, we have:

---- pages left

The summation of all must equal x, the book pages

Simplify the left-hand side

Collect like terms

Simplify

Multiply by 2