Question

shantel 's rare book collection contains 40 books . she donates 15% of her books to the national library , sells 3/5 of her books on the Internet .How many books remain in shantel's book collection ?

Answer 1

Shantel donates 15% of the 40 books to the national library.
40(.15) = 6
She also sells 3/5 of the 40 books or 60% of it.
3/5 = x/40
Cross multiply
3(40) = 5x
120 = 5x
Divide both sides by 5
x = 24

24 + 6 = 30
Subtract the number of books she sold or donated
40 - 30 = 10

Shantel has 10 books left in her book collection.