In a recent survey of monetary donations made by college graduates, the following information was obtained: 97 graduates had donated to a political campaign, 76 had donated to assist medical research, 138 had donated to help preserve the environment, 28 had donated to all three, 22 had donated to none of the three, 38 had donated to a political campaign and to medical research, 42 had donated to medical research and to preserve the environment, and 58 had donated to a political campaign and to preserve the environment. (Round your answers to one decimal place.) (a) What percent of the college graduates donated to none of the three listed causes?
%

(b) What percent of the college graduates donated to exactly one of the three listed causes?