Question

Jose has a comic book collection that he keeps among 5 shelves with an equal number on each shelf. His father adds 20 comic books to the bottom shelf, so the shelf now has 125 books. How many total books are in his collection? Use algebra to solve the equation.

Answer 1

Let x be the number of comic books on each shelf.
The bottom shelf has x + 20 comic books.
There are 5 shelves, so Jose has 5x comic books.
The total number of comic books Jose has is 5x + x + 20 = 6x + 20.
Jose's total comic book collection is 6x + 20 = 125.
Subtracting 20 from both sides, we get 6x = 125 - 20 = 105.
Dividing both sides by 6, we get x = 105 / 6 = 17.5.
Since you can't have half of a comic book, the number of comic books on each shelf is 17.
Adding all the shelves, Jose has 5 * 17 = <<5*17=85>>85 comic books in his collection. Answer: \boxed{85}.