Question

SOMEBODY HELP

Jill bought 7 books more than Sam. If Sam and Jill together have 25 books, find the
number of books Sam has.

Answer 1

Jill bought 16 books and Sam bought 9 books

Explanation:

Let the number of books that Jill bought be j.

Let the number of books that Sam bought be s.

Jill bought 7 more books than Sam:

j = 7 + s

They bought 25 books altogether:

j + s = 25

Put j = 7 + s into the second equation:

7 + s + s = 25

7 + 2s = 25

2s = 25 - 7 = 18

s = 18/2 = 9 books

Therefore:

j = 7 + s = 7 + 9

s = 16 books

Jill bought 16 books and Sam bought 9 books.