In January Mr. Tan's students read 20 books. In February, they read 15 books. What is the percent increase or decrease in the number of books the read?

In stepmber, daniel and justin opened a business. during their first three months of business, their average monthly profit was $51. if during their first month, they lost $29, and during their second month, they gained $115, what was their profit or loss for their third plzzz i will give you 299 points