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.

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. 
105 is not correct

GPT-4o mini · Answer

Let $ x $ be the number of comic books on each shelf before the additional books were added to the bottom shelf. Since there are 5 shelves, the total number of comic books in the collection is $ 5x $. According to the problem, the father adds 20 comic books to the bottom shelf, and as a result, the bottom shelf now contains 125 books. Therefore, we can set up the equation: $$ x + 20 = 125 $$ To find $ x $, we subtract 20 from both sides: $$ x = 125 - 20 $$ $$ x = 105 $$ Now that we have the number of books on each shelf, we can find the total number of comic books in the collection: $$ 5x = 5 \times 105 = 525 $$ Thus, the total number of comic books in Jose's collection is $$ \boxed{525} $$