math
posted by john on .
Of the books in a library, 1/3 came from Robbie's collection and 15 came from Marta's. Of the rest, 15 were Elena's 1/5 were Winfield's, and 5 were purchased from the bookstore. How many book are there in the library?

0.333x + 15 + 15 + 0.2x + 5 = x
0.533x + 35 = x
35 = x  0.533x
35 = 0.467x
75 = x