a collection of books went on sale , and 2 / 3 of them were sold for $ 3.50 each . if none of the 40 remaining books were sold , what was the total amount received for the books that were sold ?
n0 = 2.0
n1 = 3.0
n2 = 3.5
n3 = 40.0
t0 = n2 / n1
t1 = 1.0 / n1
t2 = n3 * t0
t3 = t2 / t1
answer = n0 * t3
print(answer)