A library contains 90 science books and some literature books
MATHEMATICS · Multi-part · CBSE · Mathematics · Probability · Probability
Problem
A library contains 90 science books and some literature books. A student selects one book at random.
(i) Given that the probability of selecting a literature book is 53, find the number of literature books currently in the library.
(ii) The librarian wishes to purchase additional science books (and no further literature books) so that after the purchase the probability of choosing a literature book falls to 21. Determine how many science books need to be purchased.