The city library donated some children’s books to Mr. Clark’s first-grade class. If each student takes 4 books?

Question

The city library donated some children’s books to Mr. Clark’s first-grade class. If each student takes 4 books, there will be 20 books left. If 3 students do not take a book and the rest of the students take 5 books each, there will be no books left. How many books were donated to the class?

Answer 1

Number of students: s

Number of books: b



b = 4s + 20

b = 5(s - 3)



Therefore:

4s + 20 = 5(s - 3)

4s + 20 = 5s - 15

s = 20 + 15 = 35



Therefore:

b = 4x35 + 20 = 140 + 20 = 160 books.

Answer 2

4

Answer 3

x = number of students

B = number of books



B = 4x + 20

B = 5(x - 3)



4x + 20 = 5(x - 3)

4x + 20 = 5x - 15

x = 35



160 books donated